earossi

My first "opportunity" to take my 993 into the Illinois Emissions Testing Facility occurred two weeks ago. Though I have been wondering when I would have an SAI issue given the >100K mileage on my car, I was shocked to find that my car FAILED the emissions check. In Illinois, they only plug into the ECU of the car and do not do tailpipe testing anymore.

The failure report indicated 2 codes, neither of which was an SAI code. The one that peaked my interest was P1691, which was related to the the Check Engine Light. When I got home, I pulled the gauge that houses the CEL and found that a PO had removed the CEL !! Easy enough to fix, but why had someone done that if not to take a triggered CEL out of the picture for a potential buyer of the car?

Before I replaced the CEL bulb and holder, I plugged in my code reader and got the two codes indicated on the failure report. I swapped out one of the other lights on that gauge to plug it into the CEL slot, and then cleared the CEL code from the ECU......and the light went out. It's now been out for about three days and 50 miles.....so, I took the car back to the emissions station and had the test repeated. This time, the car PASSED the test.

On reviewing the emissions report, it reported that no codes had been displayed but that 2 of the 7 readiness codes monitored were not set. The two were the SAI circuit and the O2 Sensor Temperature (?). There was a separate readiness code for just O2 Sensor.....but, it was shown as "Set".

So, apparently, as long as no codes are registered and there are no more than 2 readiness flags "not set", you can pass emissions in Illinois.

Does this explanation agree with what is required in other states?

MDamen

Washington is the same. For newer cars, it has to be 6 of 7 readiness set, for older, 5 of 7. And no CEL. They just hook up to the OBD2 port for 1996 and newer.