Smog Check in Eureka, CA
FAQs
Why will my vehicle fail the smog check inspection?
The most common reasons for a failed smog check are incomplete I/M readiness monitors or the malfunction indicator lamp being illuminated. Aftermarket parts that are not approved by the C.A.R.B. (California Air Resources Board) or a poorly running vehicle can also cause the vehicle to fail the inspection. The Smog Check inspection's main purpose is to ensure the original emission system has been maintained.
What are monitors?
One of the PCM's most important jobs is to make sure all the engine's sensors are working properly and that the engine isn't polluting. This is accomplished through self diagnostic software internal to the PCM. Part of OBD II enhanced software programming is a series of complex diagnostic routines that run during specific operating conditions when the vehicle is being driven. These routines, called readiness monitors, exercise the various emission systems checking for expected results. After the OBD II system has run a monitor the results are compared with a set of expected results. If the results are the same the monitor passes and if the results are not the same the monitor fails which sets the stage for triggering a DTC fault code and illuminating the check engine light.