Misfire When incomplete or no combustion occurs in one or more cylinders due to improper fuel, ignition, cylinder compression, or air. In the context of OBD II, monitor refers to any onboard diagnostic test that is executed by the PCM . A monitor is simply a diagnostic test run on a component that determines if it is operating within design specifications. The gas which makes up 78 percent of the air we breathe. Harmful gaseous emissions gases which form when nitrogen from the air is combined with oxygen under conditions of high temperature and pressure in the combustion chamber.
Oxides of nitrogen contribute the formation of ground-level ozone and photochemical smog.
A program which assesses the condition of the emission system, including the sensors and the computer itself and communicates its findings to the technician by means of diagnostics trouble codes. An on-board automotive diagnostic system required by the California Air Resources Board since 1988, which uses a microprocessor and sensors to monitor and control various engine driveability functions. OBD II expands upon OBD I to include emissions system and sensor deterioration monitoring. Normally encountered during the first few minutes of operation after a cold start. A sensor placed in the exhaust that measures exhaust oxygen content.