California OBD Inspection
 

So for 2000 and newer vehicles, they're exempt from the tailpipe test and only subject to the computer test (and visual, of course). Does anyone know exactly what kinds of data the test computer pulls from the car's OBD2 to determine whether it'll pass or fail?

Google "I/M Readiness test"

It's just looking for codes. No codes = pass

So as far as I understand, the test would look for codes and check readiness monitors as well. So if I recently clear the codes, all the monitors reset as well, and I will need to get them to be "Ready" in order to pass the test?

Yes, you need at least 5 (or 7?) monitors "ready" to pass the test.

You can't beat them by clearing codes.

Codes only go away when you fix the problem ... which is the point.

Yes so long as the code doesn't reappear and all but the EVAP monitor are ready. Just did this with intermittent 0430 code

Thanks, I have an intermittent P0430 as well. Usually happens when in heavy traffic. I used a scanner to confirm and saw that the O2 sensor after cat voltage drops or fluctuates at idle, but not when in higher RPM.

Did you pass the tet with the Evap monitor not ready?

I don't recall, but here's a quote from the pass / fail criteria:

"The failure criteria include ...OBD system reports incomplete readiness monitor(s) as specified below...Gasoline-powered vehicles model-years 2000 and newer with any incomplete monitors, excluding the evaporative system monitor

According to current CA BAR published data, the following is reason for emissions failure:

(A) Gasoline-powered vehicles model-years 1996 through 1999 with more than one (1) incomplete monitor


(B) Gasoline-powered vehicles model-years 2000 and newer with any incomplete monitors, excluding the evaporative system monitor


(C) Diesel-powered vehicles model-years 1998 through 2006 with any incomplete monitors


(D) Diesel-powered vehicles model-years 2007 and newer with any incomplete monitors, excluding the particulate filter system monitor