My buddy and i are about to dig into a 91 RS v6 that just failed emissions in missouri due to too high a Hydrocarbon count, where is the best place to start on a project like this? I think it would be to check the Oxygen sensor. Supposedly the exhuast and converter are only about 4 years old, so we have temporarily ruled that out. ALso it does have new plugs and a new cap, rotor, and wires are on there way this afternoon. ANy suggestions would be appreciated.

Thanks!

 

Hi guys, I have an 88 iroc 350tpi and failed the first time everything passed except the co reading. I went and bought some Guaranteed to Pass Emissions by CRC at an auto store and dumped it in my gas tank and went again and took the test and guess what IT PASSED....try some of that it worked for me