p.1 

OAR Box 1190 

Prepped by Candice Davis 

Document Number: 

42) ll-A-34 

Docket Number: 

A-90-28 

Printed 5/5/2008 9:13:51 AM Sheet 42 of 106 
P.2 

* 

STATE OF CALIFORNIA-CALIFORNIA ENVIRONMENTAL PROTECTION AGENCY PETE WILSON. Governor 

AIR RESOURCES BOARD 

2020 L STREET 

P.O. BOX 2815 

SACRAMENTO. CA 95812 

June U , 1995 

The Honorable Carol M. Browner 

Administrator 

U.S. Environmental Protection Agency (A-100) 

401 M Street, S.W. 

Washington, D.C. 20460 

Dear Ms. Browner: 

I. Introduction 

JU AUG 15199 5

 l!iJ 

ERA-AIR DOCKET 

In a letter dated July 21, 1994, the California Air Resources Board (ARB) requested 

that the United States Environmental Protection Agency (U.S. EPA) delay consideration of the 

ARB's request that a waiver be granted under section 209(b) of the Federal Clean Air Act 

(CAA) for its regulations regarding On-Board Diagnostic II (OBD II) System Requirements for 

1994 and Later Passenger Cars, Light-Duty Trucks (LDT), and Medium Duty Vehicles 

(MDV). The ARB requested the delay to provide it the opportunity to consider further 

amendments to the regulations that would address manufacturer concerns regarding 

technological feasibility. The ARB considered and approved amendments to the regulations at 

its December 8, 1994 Board hearing. Those amendments were formally adopted by die ARB 

on April 26, 1995, and submitted to the California Office of Administrative Law (OAL) for 

approval. The OAL approved the regulations on June 8, 1995. With approval of the 

regulations, the ARB respectfully requests that the U.S. EPA reactivate California's waiver 

request and consider the OBD II regulations, as amended, at its earliest convenience. 

In its submission, dated September 15, 1992, the ARB initially requested that the U.S. 

EPA find the OBD II regulations to be within the scope of existing waivers. In that 

submission, the ARB provided a summary of the OBD II regulation, as amended on 

July 22, 1992. In a letter dated September 14, 1993, the ARB reconsidered its request and 

asked for a new waiver, rather than a finding that the regulations are within the scope of 

existing waivers. In that letter, the ARB informed the U.S. EPA that it had amended the 

regulations for a second time on July 9, 1993 to address certification problems that a few 

manufacturers were experiencing in the 1994 and 1995 model years. At this time, the ARB 

requests that the U.S. EPA incorporate by reference the summary of the regulations as set 

forth in the September 15, 1992 letter, and the entire September 14, 1993 letter, including the 

waiver analysis. 
P.3 

,• , 4 

The Honorable Carol M. Browner 

At the December 8, 1994 Board hearing, the Board approved amendments to the 

regulations that address, among other things, continuing manufacturer concerns with 

developing fully compliant monitoring systems by the 1996 model year. (A copy of the 

"Notice of Public Hearing to Consider Technical Status and Proposed Revisions to 

Malfunction and Diagnostic System Requirements for 1994 Model-Year Passenger Cars, 

Light-Duty Trucks, and Medium Duty Vehicles and Engines" (Notice), the "Staff Report: 

Initial Statement of Reasons for Rulemaking" (Staff Report), Resolution 94-67, and "Notice of 

Availability of Modified Text" are enclosed herewith and respectively identified as 

Attachments 1-4.) Specifically, the amendments relate to problems manufacturers have 

experienced in developing enhanced diagnostic systems to monitor catalysts used in lowemission vehicles (LEV) and misfire detection. In recognizing the technology forcing nature 

of the regulations and the number of different monitoring strategies manufacturers are required 

to develop in the early years of implementation of the regulations, the Board also adopted 

amendments that would afford manufacturers additional compliance flexibility. At the 

hearing, the Board also approved amendments to the monitoring requirements for evaporative 

system leaks and for the monitoring of diesel and alternate fuel vehicles. Regarding the last 

amendment, to make the amendment consistent with the requirements for alternative fueled 

retrofit systems, the Board amended sections 2030 and 2031 of Title 13, California Code of 

Regulations (CCR), and the incorporated "California Certification and Installation Procedures 

for Alternative Fuel Retrofit Systems for Motor Vehicles Certified for 1994 and Subsequent 

Model Years." (See Notice and Staff Report, Attachments 1 and 2 respectively.) 

A summary of the substantive amendments adopted by the Board at the 1994 hearing 

follows. A detailed explanation of the technological feasibility and the cost effectiveness of 

the amendments are provided in Attachment 2, the Staff Report. 

II. Summary of Amendments 

A. Catalyst Monitoring: 

The adopted amendments remove the requirement for independent evaluation of front 

catalyst efficiency on LEV applications, and instead require an overall catalyst system 

evaluation in which the malfunction criteria will be based on tailpipe emissions. Specifically, 

the amendments require the manufacturer to monitor the catalyst system so that malfunctions 

are indicated before tailpipe emissions exceed 1.5 times the hydrocarbon standard of the 

vehicle. The resulting monitoring of the entire system addresses manufacturer concerns that 

the regulations afford them greater flexibility in designing catalyst systems. At the same time, 
P.4 

The Honorable Carol M. Browner 

the amendments provide the ARB with greater assurance that malfunctions will be properly 

detected in all catalyst configurations. 

In adopting the above amendments, the Board determined that manufacturers may have 

to modify some of their current monitoring system designs to fully meet the revised 

requirements. The Board thus provided manufacturers with additional lead time for 

compliance and determined that the new monitoring requirements be phased in over three years 

beginning in the 1998 model year. The proposed phase-in schedule would require that 30 

percent of a manufacturer's projected LEV sales for the 1998 model year comply with the new 

catalyst requirements; 60 percent in the 1999 model year; and 100 percent in the 2000 model 

year. 

In the interim (model years 1996 and 1997), all vehicles certified to the transitional 

LEV (TLEV) standard would be required to indicate a malfunction when emissions exceeded 

2.0 times the TLEV hydrocarbon (HC) standard plus the 4000 mile emission level rather than 

the 1.5 times the standard which is required in the 1998 model year. All vehicles certified to 

the LEV standard would be required to indicate a malfunction at 2.5 times the LEV HC 

standard plus the 4000 mile emission level. The interim standards will permit manufacturers 

to implement catalyst monitoring strategies on existing vehicle designs without requiring 

hardware modifications and should provide manufacturers with the necessary lead time to 

properly design systems that will meet the 1.5 times the standard requirement. 

B. Misfire Detection Monitoring: 

The OBD II regulations initially adopted by the Board in 1989, required that 

commencing with the 1994 model year, manufacturers were expected to monitor engine 

misfire throughout the full engine operating speed and load range. In 1991, after reviewing 

industry's progress in developing the necessary technology to meet the misfire detection 

requirements, the Board delayed implementation for monitoring over the full speed and load 

range until the 1997 model year, and in the interim required misfire detection only during 

operating conditions within the scope of a Federal Test Procedure test. 

At the December 1994 Board hearing, after a further review of industry's progress, the 

Board concluded that by the 1997 model year manufacturers should be able to certify a 

significant percentage of vehicles with misfire detection systems that operate over almost the 

full speed and load engine operating range. The only portion of the range that could not be 

fully monitored would be at engine speeds above 3000 revolutions per minute with very light 

engine load. Such operating conditions are not encountered often. Upon consideration of 

industry's progress, the Board amended the regulations to provide that the manufacturers may 

disable the monitoring system over that portion of the range identified above. In addition, the 
P.5 

The Honorable Carol M. Browner 

Board amended the implementation schedule to allow manufacturers to certify their product 

line according to the following phase-in schedule: 50 percent of the manufacturer's projected 

sales volume in the 1997 model year; 75 percent in the 1998 model year; 90 percent in the 

1999 model year; and 100 percent in the 2000 model year. The phase-in schedule provides 

manufacturers with additional lead time to implement misfire detection on the more 

challenging engine designs, including engines with a high number of cylinders. 

C. Evaporative System Leak Detection: 

In 1991, the Board adopted a requirement that manufacturers develop for 1996 and 

later model year vehicles a monitoring strategy to detect evaporative system leaks as small as 

.040 inches in diameter. Realizing the increasing relative contributions of evaporative HC 

emissions in the formation of ozone, the Board, at the December 1994 hearing, amended the 

regulations to require that manufacturers phase-in a more stringent monitoring strategy 

commencing with the 2000 model year. The amended regulation would require that 

manufacturers develop a strategy to detect leaks as small as .020 inches in diameter. Data 

taken from in-use vehicles indicate that a significant number of vehicles have evaporative 

systems leaks approximately equivalent in magnitude to a .020 inch leak, and that the excess 

evaporative emissions from such vehicles are significant. These data are presented in the 

attached Staff Report. The amended regulations would require that manufacturers phase-in the 

new requirement using the following schedule: at least 50 percent of a manufacturer's 

projected sales volume must comply with the .020 inch diameter monitoring strategy in the 

2000 model year; at least 75 percent in the 2001 model year, and 100 percent in the 2002 

model year. 

D. Requirements For Diesel Vehicles: 

In 1991, the Board adopted amendments to the regulation making the OBD II 

requirements applicable to diesel engines beginning with the 1996 model year. However, at 

that time the Board recognized that some OBD II requirements for spark ignition vehicles 

would not be applicable to diesel engines, and that insufficient information on necessary 

technology was not available to specifically set forth monitoring requirement for diesel 

engines. Therefore, the regulations only required diesel manufacturers to submit an OBD II 

monitoring plan for the ARB's review. 

At the December 1994 hearing, the Board concluded that sufficient information 

presently exists to more specifically detail the minimum monitoring requirements for diesel 

applications. Accordingly, the regulations were amended to provide that manufacturers of 
The Honorable Carol M. Browner 

diesel vehicles implement monitoring strategies for misfire, the fuel system, the exhaust gas 

recirculation (EGR) system, and any electronic components that can affect emissions when 

malfunctioning. 

As for misfire monitoring, additional lead time (until the 1998 model year) was 

provided. Beginning with this model year, manufacturers are required to develop a strategy 

capable of detecting the. complete loss of combustion in one or more cylinders. The 

amendment provides that the strategy would need to be active only during certain operating 

conditions (e.g., during idle), and that monitoring would be required only once per driving 

cycle. For fuel system monitoring, the amendments require that manufacturers attempt to 

develop, to the extent feasible, monitoring strategies that can detect fuel system malfunctions 

that cause diesel vehicles to exceed 1.5 times any of the applicable emission standards. 

Manufacturers would not be responsible for detecting malfunctions for which the system is 

incapable of providing necessary feedback, such as a fuel injector with a broken tip. The 

monitoring requirements for EGR performance and electronic components would be the same 

as for spark-ignition vehicles under the amendments. 

E. Alternate Fuel Vehicles: 

Prior to the 1994 amendments, the regulation required vehicles designed to operate on 

alternate fuels to comply with the OBD II requirements beginning with the 1996 model year. 

Recognizing manufacturer concerns that insufficient leadtime existed to develop fully 

compliant OBD II monitoring strategies that are compatible with the use of alternate fuels by 

the 1996 model year, the Board amended the regulation to provide an additional three years of 

leadtime for full compliance. For the 1996-1998 model years, manufacturers would be 

required to implement diagnostic strategies to the extent feasible, but would not be required to 

include monitoring strategies directly related to the use of alternate fuels. Similarly, the Board 

amended California's certification procedures for alternate fuel retrofit vehicles to permit 

retrofit system manufacturers the same flexibility as provided to original equipment 

manufacturers. Accordingly, full compliance with the OBD II requirements is not required 

until the 1999 model year. These procedures are referenced by sections 2030 and 2031 of 

Tide 13, CCR. 

F. Tamper Resistance: 

The Board adopted amendments that make more specific the anti-tampering 

requirements that motor vehicle manufacturers need to follow to protect OBD II system 

calibrations. Under the amendments, manufacturers are required to use reprogramming 

strategies that require access to a centralized computer maintained by the manufacturer, and 

the use of full data encryption. However, manufacturers, with the Executive Officer's 
P.7 

The Honorable Carol M. Browner 

approval, may develop alternative, but equivalent, programming protection. Recognizing that 

manufacturers will need lead time to implement these protections, the regulation does not 

require full compliance until the 1999 model year. 

G. 1996-2000 Model Year Compliance: 

At the December hearing, the Board acknowledged that the OBD II regulations require 

the implementation of a significant number of technology forcing monitoring strategies and 

that manufacturers may experience unanticipated problems in developing systems despite good 

faith efforts to comply with the regulations. Accordingly, the Board amended the regulations 

to provide manufacturers with some compliance relief for the 1996-2000 model years. 

The amendments are similar in nature to the relief provided in 1993 for the 1994 and 

1995 model years. In 1993, the Board amended the regulations to permit 1994 model year 

vehicles equipped with OBD II systems to be certified even if one or more of the monitoring 

strategies did not meet the minimum requirements of the regulation. For 1995 model year 

vehicles, certification is also permitted even though the OBD II system may have deficiencies. 

However, if a particular engine family has more than two deficiencies, the manufacturer will 

be assessed fines of $25 or $50 per vehicle for each deficiency above the second. 

The amendments adopted in December provide that for 1996 model year vehicles, the 

Board will continue to provide the same relief that it has been providing for 1995 model year 

vehicles. In calculating deficiencies, electronic transmission deficiencies would be counted as 

a single deficiency. 

For the 1997-2000 model years, the amendments would continue to permit 

manufacturers to certify OBD II systems with deficiencies. However, in most instances, the 

number of permitted deficiencies for a vehicle model without incurring a fine would be 

reduced to one. A manufacturer would incur a fine on its first deficiency if a monitoring 

strategy were completely absent from the monitoring system. In addition, a manufacturer 

would not be allowed to carry over monitoring system deficiencies from one year to the next 

unless it were able to demonstrate that vehicle hardware modifications would be necessary to 

correct the deficiencies, in which case a one year carry-over would be permitted. 

In providing for such latitude in certifying OBD II systems, the Board recognized the 

complexity of the monitoring requirements for catalysts, evaporative system leaks, and misfire 

detection. It further recognized the high degree of technical innovation required of 

manufacturers to properly apply the requirements to newly introduced LEVs. 
P.8 

The Honorable Carol M. Browner 

H. Other Modifications: 

In addition to the above, the Board adopted several other less substantive amendments 

fof the purpose of clarifying the regulations. These amendments are identified, with 

explanations, in the Staff Report that is enclosed herewith. 

III. Waiver Analysis 

A. The OBD II Regulations Should Be Granted a Waiver as an In-Use Enforcement 

Procedure: 

In my September 14, 1993 letter, the ARB submitted a detailed waiver analysis. In 

that analysis, the ARB followed the principles outlined by the Administrator and the courts in 

the consideration of waivers of enforcement procedures. For such analyses, the U.S. EPA 

considers only whether the subject enforcement procedure undermines a previously determined 

protectiveness determination and whether the enforcement procedure is consistent with the 

intent of section 202(a) of the CAA. (Motor and Equipment Manufactures Assn [MEMA] v. 

EPA [1979] 627 F.2d 1095, 1120.) 

1. Protectiveness Determination: 

In the above-referenced analysis, I noted that the ARB has adopted emission standards 

for each class of vehicles for which the OBD II regulations would apply. In that letter, I 

further explained that California had requested and received from the U.S. EPA section 209(b) 

waivers for each of the classes of vehicles for which the ARB had adopted standards. (See 

e.g., 49 FR 18887 [May 5, 1984]; 47 FR 1015 [January 8, 1982]; 46 FR 36237 

[July 14, 1981].) More recently, the Administrator has approved waivers for new standards 

adopted by the ARB for California's LEV program and for LDTs, MDVs, and light heavyduty vehicles and engines. (58 FR 4688 [January 7, 1993] and 59 FR 48625 

[September 22, 1994].) 

In the September 14, 1993 letter, I concluded that the OBD II regulations do not 

undermine the previously issued waivers for on-road motor vehicles. That conclusion is 

consistent with the findings made by the ARB in each of the resolutions that were adopted at 

the time of approving the OBD II regulations. Specifically, in the letter, I stated that the 

OBD II regulations would not undermine the existing emission standards because the mandated 

OBD II systems are significantly more advanced than the first generation monitoring systems 

that are replaced. The OBD II regulations should thus better assure that the emission 
P.9 

The Honorable Carol M. Browner 

reductions promised by the adopted standards are actually achieved in-use, because they will 

be more effective in detecting and aiding in the diagnosis of emission-related malfunctions. 

The ARB staff had estimated that by the year 2010 the OBD II regulations would achieve inuse emission reductions of 125 tons per day of HCs, 125 tons per day of Oxides of Nitrogen 

(NOx), and 2000 tons per day carbon monoxide (CO). 

Further, in my letter, I compared the OBD II regulations, as they existed in September 

1993, to the federal OBD regulations that were promulgated in February 1993, and concluded 

that the California regulations were significantly more stringent. I reached this conclusion 

upon finding that the OBD II regulations require the monitoring of more emission-related 

components and systems and establish lower emissions thresholds for indicating malfunctions, 

particularly on LEV applications, than do the federal regulations. 

The most recent amendments to the OBD II requirements, although providing 

manufacturers with increased flexibility for compliance, still require the implementation of 

diagnostic systems that are far more effective than those required by first generation on-board 

diagnostic regulations (OBD I, Title 13, CCR, section 1968), and do not undermine the 

waivers that have been issued for the on-road California motor vehicle program. The OBD II 

regulations will continue to assure that in-use vehicle emission performance will remain near 

certification levels for the life of the vehicle. 

Additionally, the OBD II regulations, as amended,.continue to mandate more 

comprehensive and stringent on-board monitoring strategies than the recently noticed direct 

final rulemaking issued by the U.S. EPA. (60 Fed.Reg. 15242 [March 23, 1995].) The stated 

purpose of that rulemaking was to align the federal regulations with the adopted OBD II 

amendments. Upon review of the federal rulemaking, it is clear that the OBD II requirements 

for catalyst and misfire monitoring remain more stringent than the federal requirements. Like 

the OBD II regulations, the federal regulations were also amended to provide similar types of 

compliance relief to manufacturers. The federal rulemaking allows manufacturers to certify 

systems with limited deficiencies and provides them with additional lead time to develop some 

monitoring strategies for alternate fuel vehicles. 

2. Consistency with CAA Section 202(a): 

In my September 14, 1993 letter, I stated that after a thorough review of applicable 

case law and the U.S. EPA waiver determinations, the ARB believed the OBD II regulations, 

as amended on that date, to be consistent with section 202(a) of the CAA. Upon consideration 

of the most recent amendments, I reaffirm my conclusion on this point. Under established 

precedent, the U.S. EPA will find California's regulations to be consistent if (1) they provide 

adequate lead time to permit the development of technology necessary to meet the 
The Honorable Carol M. Browner 

requirements, giving appropriate consideration to the cost of compliance, and (2) the 

California test procedures set forth in the regulations permit manufacturers to meet both the 

federal and California test procedures with the same test vehicle. 

As stated in my previous letter, the ARB has provided manufacturers with substantial 

lead time since initially approving the regulations for adoption in 1989. For the 1994 and 

1995 model years, the first years subject to the regulations, manufacturers were afforded 

nearly four years of lead time to develop enhanced monitoring systems. Moreover, the 

requirements applicable to 1994 and 1995 model years only applied to those models for which 

manufacturers voluntarily elected to install enhanced monitoring systems. 

For the 1994-95 model years, several manufacturers were able to certify fully 

compliant monitoring systems; however, other manufacturers applied for and received 

exemptions and were not required to comply with the monitoring requirements. In addition, as 

described in the summary above, the Board amended the regulations in 1993 to provide 

certification relief for those manufacturers who were unable to comply with the requirements 

for the 1994-95 model years despite good faith efforts. 

Beyond its efforts to provide certification flexibility as it did with the 1993 

amendments, the ARB has committed itself to assuring the technological feasibility of the 

regulations by periodically reviewing the regulations. As part of this review process, the 

Board approved amendments to the regulations in 1991. These amendments, in part, 

addressed manufacturer concerns about the technical feasibility of meeting the monitoring 

requirements as originally adopted. The amendments also attempted to make the regulations 

more effective and consistent with the OBD requirements then being proposed by the U.S. 

EPA. The amendments primarily focused on new monitoring strategies for catalysts on LEVs, 

evaporative system leaks, and engine misfire. 

To the extent that the 1991 amendments required new monitoring strategies, 

manufacturers were provided with additional lead time and greater compliance flexibility. The 

September 1993 letter described in detail these new requirements and the ARB's reasons for 

believing that the regulations, as amended, were technologically feasible in the timeframes 

provided, given the costs for compliance. 

At the Board's direction, the ARB staff has continued to monitor the progress of 

manufacturers in achieving compliance. Over the past several years, the ARB staff has met 

with manufacturers in both private and general workshops. At its December 1994 hearing, in 

response to continuing concerns expressed by manufacturers regarding development and 

implementation of monitoring strategies for LEV catalysts and engine misfire detection, the 

Board adopted the aforementioned amendments that are summarized in the previous section. 
P.11 

The Honorable Carol M. Browner 10 

In addition to addressing the compliance concerns raised by the manufacturers, the Board 

provided them with additional lead time and compliance flexibility. 

To the extent that the amendments also imposed new, tighter restrictions for 

evaporative leak detection monitoring, the Board provided manufacturers with more than five 

years of lead time before they would have to begin phasing-in the more stringent requirements. 

A detailed discussion of the technological feasibility of the regulations is set forth in the 

Staff Report, Attachment 2. For the reasons set forth in the Staff Report and in the preceding 

discussion, the ARB believes that all of the requirements of the OBD II regulations are 

technically feasible given the lead time provided and the costs of compliance. 

The second prong ofthe consistency test, as developed by the U.S. EPA, is that the 

California standards and accompanying enforcement procedures would be found to be 

inconsistent with comparable federal regulations if one vehicle could not comply with both the 

California and federal test procedures. As explained in the September 1993 letter, this 

problem does not exist for the OBD regulations in that the ARB and the U.S. EPA have 

worked closely in developing their respective OBD strategies. The federal OBD rule provides 

that through the 1998 model year compliance with the California OBD II requirements will 

satisfy the requirements of the federal rule. (40 CFR Part 86, section 86.094-17(j).) 

Similarly, the OBD II regulations provide that after the 1998 model year, California will 

accept compliance with the federal OBD requirements for non-LEVs. Presently, there are no 

federal LEV standards; thus, no inconsistency exists between federal and state regulations as to 

these vehicles. 

B. In the Alternative, if the U.S. EPA Were to Find the OBD II Regulations 

Establish New Emission Standards, a Waiver Should, Nonetheless, be Granted. 

Although the ARB strongly continues to believe that its OBD II regulations are in-use 

enforcement measures and the Administrator should grant a waiver under the analysis 

presented above, it has been argued that the OBD II regulations are, in fact, new emission 

standards that require a full analysis of the three criteria for denying a waiver set forth in 

section 209(b) of the CAA. To the extent that the U.S. EPA adopts this view, the ARB 

provides the following analysis to show that regardless of how the OBD II regulations are 

characterized, there is no basis for the Administrator to deny this waiver request. 

Under section 209(b), to grant a waiver for a new emission standard, California must 

make a determination that the adopted standards will be, in the aggregate, at least as protective 

of public health and welfare as applicable federal standards. Once such a determination is 
P.12 

The Honorable Carol M. Browner 11 

made, the Administrator must grant the waiver unless she finds that the determination by 

California is arbitrary and capricious; that California does not need state standards to meet 

compelling and extraordinary conditions; and the California standards and accompanying 

enforcement procedures are not consistent with section 202(a) of the CAA. 

1. Protectiveness Determination: 

In its September 14, 1993 letter to the Administrator, the ARB presented a detailed 

comparison of the OBD II regulations and the federal OBD regulations. As previously stated, 

in that letter I concluded that the OBD II regulations are more stringent than the applicable 

federal OBD regulations. This conclusion was made after considering both the scope of 

emission-related components and systems for which an on-board evaluation of performance is 

required and the level of performance at which a malfunction is to be indicated by the 

diagnostic systems under the respective regulations. (See September 14, 1993 letter, at 

pages 3-5.) 

The most recent amendments do not affect the comparable stringency of the OBD II 

regulations. Although the amendments provide some compliance relief to manufacturers for 

meeting the catalyst requirements for LEVs and for misfire monitoring, the OBD II 

requirements continue to be more stringent than the federal regulations. With respect to 

monitoring catalyst system performance, the OBD II emission thresholds for the Malfunction 

Indicator Light (MIL) illumination on LEVs are significantly lower than the .6 grams per mile 

permitted under the federal regulations (by a factor as great as 10 on Ultra-LEVs (ULEV)). 

For non-LEVs (i.e., vehicles meeting the federal tier one standards, or California's 

equivalent), the emission threshold is purposefully comparable to that specified in the federal 

regulations. Regarding misfire detection, the OBD II regulations continue to require that the 

MIL be illuminated to indicate misfire detection when emissions caused by misfire cause 

emissions to increase by more than 1.5 times the applicable standard, which is more stringent 

with respect to all current emission standards than the federal OBD emission thresholds (0.4 

g/mi HC, 3.4 g/mi CO and 1.0 g/mi NOx). Further, the OBD II regulation requires misfire 

detection over a greater engine operating range than does the federal requirements. 

In addition, the OBD II regulations, as amended, have been made more stringent by 

requiring, commencing in the model year 2000, that monitoring systems detect evaporative 

system leaks as small as 0.02 inches in diameter. The federal regulations presently provide for 

MIL illumination when emissions equal or exceed the emissions that would escape from a hole 

of 0.04 inches in diameter. Further, the federal OBD requirements permit manufacturers to 

forego monitoring of the evaporative system if evaporative diurnal emissions do not exceed 30 

grams per test. Based on recent data from manufacturers, the evaporative system will likely 
P.13 

The Honorable Carol M. Browner 12 

not have to be monitored on many vehicles under this provision. The OBD II regulations do 

not contain such a provision. 

Finally, although the amendments provide manufacturers with additional flexibility in 

certifying non-fully compliant systems in the 1996-2000 model years, the amendments do not 

provide for such a significant relaxation of standards that the California regulations are no 

longer as stringent as the federal regulations. As previously stated, the federal OBD 

requirements were recently amended to provide for certification of vehicles with deficiencies 

through the 1998 model year. Although California's deficiency provisions extend for an 

additional two years, they restrict the number of deficiencies permitted without penalty to one 

per vehicle model, and impose additional restrictions regarding the complete absence of a 

monitoring strategy and the carry-over of monitoring deficiencies from one model year to the 

next. By the 1999 model year, the ARB expects that the need for certification with a 

deficiency will be rare since manufacturers will have had several years experience with OBD II 

systems. Further, even if an OBD II equipped vehicle is certified with a deficiency, the OBD 

II system should still be more effective overall than a system meeting the federal requirements 

for the reasons previously given. That is, the OBD II regulations require monitoring of many 

more emission-related components and establish malfunction criteria significantly more 

stringent than required under the federal regulations. 

Accordingly, for all the foregoing reasons, the ARB finds that the California OBD II 

regulations are, in the aggregate, at least as stringent as the comparable federal OBD 

regulations. The ARB further believes that no basis exists for the Administrator to conclude 

that this determination by the ARB is arbitrary and capricious. 

2. The Regulations Are Necessary to Meet Compelling and Extraordinary Conditions 

in California 

California needs its own motor vehicle program to meet serious air pollution problems 

unique to the state. The Administrator has previously and consistently recognized this need 

when granting waivers for motor vehicles under section 209(b) of the CAA. Given the serious 

air pollution problems faced by California and the resulting need to achieve the maximum 

reductions in emissions, the California Legislature and the ARB continue to believe that it is 

imperative that California continue its emission control programs for motor vehicles. (See 

California Health and Safety Code sections 43000.5, 43013, 43018, and 43101 et seq.) 

The relevant inquiry under this criterion is whether California needs its own emission 

control program to meet compelling and extraordinary conditions, not whether any given 
P.M 

The Honorable Carol M. Browner 13 

standard is necessary to meet such conditions.1 The Administrator has determined in 

approving waivers under section 209(b) that the phrase "compelling and extraordinary 

conditions" refers to: 

".. . certain general circumstances, unique to California, primarily responsible 

for causing its air pollution problem [including] . . . geographical and climatic 

factors [as well as] .. . the presence and growth of California's vehicle 

population, whose emissions were thought to be responsible for ninety percent 

of the air pollution in certain parts of California." 

Thus, the Administrator has stated: 

"It is evident. . . that 'Compelling and extraordinary conditions' does not refer 

to levels of pollution directly, but primarily to the factors that tend to produce 

them: geographical and climatic condition that, when combined with large 

numbers and high concentrations of automobiles, create serious air pollution 

problems."2 

California, and the South Coast Air Basin in particular, continues to experience the 

worst air quality in the nation. (See Approval and Promulgation of State and Federal 

Implementation Plans; California-Sacramento and Ventura Ozone; South Coast Ozone and 

Carbon Monoxide; Sacramento Ozone Reclassification (40 CFR Parts 52 and 81, 59 Fed.Reg. 

23264).) The unique geographical and climatic conditions, and the tremendous growth in 

vehicle population and use which moved Congress to authorize California to establish separate 

vehicle standards in 1967 are still in existence today. In the California Clean Air Act of 1988, 

the California Legislature found: 

That despite the significant reductions in vehicle emissions which have been 

achieved in recent years, continued growth in population and vehicle miles 

traveled throughout California have the potential not only to prevent attainment 

of the state standards, but in some cases, to result in worsening of air quality. 

(California Health and Safety Code section 43000.5.) 

However, when the California Standards have been measured against the tests in these cases, the 

Administrator has recognized that such a test, if applied to California, "would not be applicable to its fullest 

stringency due to the degree of discretion given to California in dealing with its mobile source pollution problems," 

(41 Fed.Reg. 44209, 44213, [October 7, 1976]; 49 Fed.Reg. 18887, 18892 [May 3, 1984]). 

2

 See, e.g., 46 Fed.Reg. 2371, 26373 (May 12, 1981); 43 Fed.Reg. 32182 (July 25, 1978). 
The Honorable Carol M. Browner 14 

In response to the undisputed severe air quality problems in California, the California 

Legislature authorized the Board to consider adopting inter alia, the most cost-effective 

combination ofcontrol measures for all classes of motor vehicles, including further reductions 

in exhaust and evaporative emissions and reductions in emissions from in-use motor vehicles 

from improvements in emission system durability and performance. (California Health and 

Safety Code sections 43013 and 43018.) Accordingly, for all the aforementioned reasons, 

there can be no doubt of the continuing existence of compelling and extraordinary conditions 

justifying California's continued need for its own motor vehicle and engine emissions control 

program. 

3. The Regulations Are Consistent with Section 202(a): 

For the reasons set forth above in section III. A.2, the ARB believes that there is no 

basis for the Administrator to conclude that the OBD II regulations are inconsistent with the 

two-prong test for consistency. 

IV. Conclusion 

Based on the foregoing, I believe that the U.S. EPA should grant California's waiver 

request for the OBD II regulations. The regulations, which the ARB believes to be 

accompanying enforcement procedures, do not endanger the protectiveness findings that the 

ARB has made for previously granted waiver determinations and the regulations are consistent 

with the intent of section 202(a) of the federal CAA. In the alternative, if the OBD II 

regulations are viewed as new emission standards, a waiver should also be granted. The 

regulations, as amended, are, in the aggregate, at least as stringent as the comparable federal 

OBD regulations, California needs its own motor vehicle program to meet compelling and 

extraordinary conditions in the state, and, as stated, the regulations are consistent with the 

intent of section 202(a) of the CAA. With regard to the consistency criterion under the 

alternative analyses, the ARB has demonstrated that the technology is either presently 

achievable, the regulations are'sufficiently flexible for compliance, or that the lead time 

provided is sufficient. In this letter and in previous submissions, the ARB has addressed the 

criteria for lead time set forth in the appellate court decision, Natural Resource Defense 

Council v. EEA (D.C. Cir. 1981) 655 F.2d 318, and affirmatively answered all theoretical 

objections to the projected technology, identified the major steps necessary in refining the 

technology, and offered plausible reasons for believing that each of the identified steps can be 

completed in the time available. 
P.16 

>"- . -s< 

The Honorable Carol M. Browner 15 

The following list of documents relating to the board hearing on December 8, 1994 are 

enclosed: 

1. "Notice of Public Hearing to Consider Technical Status and Proposed Revisions 

to Malfunction and Diagnostic System Requirements for 1994 Model-Year 

Passenger Cars, Light-Duty Trucks, and Medium Duty Vehicles and Engines" 

2. "Staff Report: Initial Statement of Reasons for Rulemaking" 

3. Resolution 94-67 

4. "Notices of Availability of Modified Text," issued January 19, and 

April 3, 1995 

5. "Final Statement of Reasons for Adoption of Amendments to the Malfunction 

and Diagnostic System Requirements for 1994 Model-Year Passenger Cars, 

Light-Duty Trucks, and Medium Duty Vehicles and Engines" 

6. Executive Order G-95-016, dated April 26, 1995, formally adopting the 1994 

amendments 

7. Face Sheets for the filing of the 1994 rulemaking with the California OAL, and 

attached Title 13, California Code of Regulations, section 1968.1, as amended 

Should you have any questions or need further assistance, please contact 

Mr. Steve Albu, Chief, Engineering Studies Branch, Mobile Source Division, at 

(818) 575-7010. Legal questions may be addressed to Michael Terris, Senior Staff Counsel, 

at (916) 322-3283. 

Sincerely, 

Enclosures