There are two types of tests to measure the vehicle's exhaust. 1980 and older model year vehicles, and all vehicles with a manufacturer's designated gross vehicle weight rating of 8,501 to 10,000 pounds, receive a two-speed idle test. This test measures hydrocarbons and carbon monoxide at 2,500 rpm and curb idle. This type of test is performed to measure nitric oxide, as well as hydrocarbons and carbon monoxide. These vehicles will be tested using the two-speed idle test.
Most vehicles receive an emissions control component inspection.
The inspector will check for emissions control systems that were originally installed on the vehicle by the manufacturer. Most vehicles will also receive a gas cap pressure test. The safety inspection is required once a year. The month and year on the windshield sticker indicate when the vehicle needs to be inspected. If the vehicle fails the inspection, the vehicle is eligible for ONE free retest at the original emissions inspection station within 14 calendar days of the Initial inspection.