i just went to get my car smogged and it failed because the CO and HC levels were too high. the car is stock other than a cold air intake and it has a aftermarket o2 sensor on the stock b1b with 200k miles. The tech said that the o2 is making the car run rich, Is there anything else I can do to help me pass? I dont want to fix one thing and keep goin back for a retest, so I want to just do everything and get it to pass. Let me know what other problems it could be.


Modified by bmxer at 4:52 PM 7/10/2007

 

It could be many different things but personally the first thing i would do is replace the aftermarket O2 for OEM. Unless the tech used a lab scope on the o2 signal he is guessing as much as i am. A biased lean O2 could deffinately make the car run rich by sending a false lean signal to the PCM which in return would increase the Short/Long term fuel trim.