Emission testing in Illinois is a pain, but easy to deal with, mostly. They used to do a tailpipe sniff and visual inspection on carbureted cars all the way through the obd1 efi era. As EFI advanced and obd2 evolved, they just plug in to the Aldl and scan for codes, and test the gas cap. As long as the pcm is happy the state is happy. So only obd2 cars are tested. I'm pretty sure the mandatory year is 1996 and newer. My car has never had a problem passing
The other issue is they only test in a few areas. The 6 counties around Chicago and a handful of counties around the St Louis area. I live about 50miles south of Chicago and have to test. They tie it to the license plate.. No successful test? No sticker...
As far as the obd1/2 knock sensor issue, I read about some guys doing the resistor mod. I thought maybe building a small switched circuit to select obd1or 2 with a switch and not have to fight with getting the car on jacks and loosing antifreeze to swap the sensor around might make it a bit more palatable since a pcm swap would only be a 10 minute job uptop... do you know what happens if the wrong sensor is plugged into the incorrect pcm? Does it damage the pcm, or just code out?
Black 1997 Ss Convertible
383 6speed 4:10
Last edited by Speeda18!; 11-25-2017 at 09:42 AM.