How does OBD II work for emissions testing?
A single misfire will cause a subtle change in the speed of the crank. OBD II tracks each and every misfire, counting them up and averaging them over time to determine if the rate of misfire is abnormal and high enough to cause the vehicle to exceed the federal emissions limit.
What should I do if my OBDII catalyst is not ready?
Accelerate back to 55 to 60 mph at half throttle. During this step the OBDII system will look for misfires, fuel trim and EVAP purge. 6. Hold at a steady speed of 55 to 60 mph for 5 minutes. Catalytic converter efficiency, EGR flow, ignition misfire, fuel trim, EVAP system and oxygen sensors operation will now be checked.
How are O2 sensors and catalytic converter diagnostics fail?
O2 SENSORS & CATALYTIC CONVERTER DIAGNOSTICS Converters typically fail one of two ways: they get too hot, melt and plug up, or the catalyst becomes contaminated and useless.
How is EVAP performed in the OBDII drive cycle?
The Evap “bypassing” procedure is described in the following drive cycle. The OBDII Drive Cycle will be performed using a scan tool. Consult the instruction manual for each described function. NOTE: A detailed description of a Powertrain Control Module (PCM) Reset is found in this section, refer to the table of contents.
O2 SENSORS & CATALYTIC CONVERTER DIAGNOSTICS Converters typically fail one of two ways: they get too hot, melt and plug up, or the catalyst becomes contaminated and useless.
Accelerate back to 55 to 60 mph at half throttle. During this step the OBDII system will look for misfires, fuel trim and EVAP purge. 6. Hold at a steady speed of 55 to 60 mph for 5 minutes. Catalytic converter efficiency, EGR flow, ignition misfire, fuel trim, EVAP system and oxygen sensors operation will now be checked.
How can I tell if my OBD 2 car has an emissions problem?
An OBD II vehicle with a converter efficiency code may or may not have an emissions problem. The only way to know for sure is to give it an emissions test. But here’s the catch. Even if it passes a tailpipe test, it may not be emissions legal as long as the MIL lamp remains lit.
What’s the purpose of the OBD2 readiness monitor?
The purpose of the OBD2 drive cycle is to let your car run on-board diagnostics. This, in turn, allows the readiness monitors to operate. And detect potential malfunctions of your car’s emission system. The correct drive cycle for your car can vary greatly depending on the car model and manufacturer.