ok, about a year ago i put a jackson racing high flow cat on my 2000 civic si, worked fine for a while then the cel appered, finally fixed it by installing a ziptech o2 simulator and the cel has been off ever since. Just recently i had a skunk manifold and 68 mm skunk tb put on an the car ran fine tonite though the cel came on so i went to autozone and the obd2 scanner said that the #1 cylinder was too lean, also i have a vafc with the correction on -14, what do you think the problem is the o2 sim, afc or something else please help thankyou

 

hmmm.

 

hrm, that is awefully strange.... Do you think that you might have too much backpressure from your exhaust? Some how I have this dumb feeling that you might be looking at having to replace your injector. Do you have any exhaust leaks anywhere that might contribute to a strange o2 sensor not working properly? does it burn oil, because if it does, then it will carbonize the o2 sensor and it could relay wrong information to the ECU and return change your fuel to air ratio. I would suggest starting witch checking your 02 sensor

 

If you cannot be helpful don't post.

I would take off the VAFC first and see if that clears everything up. If not set right you could really screw up your car.

 

well i went down to a local shop today and we located the problem, the afc was tuned for the stock manifold and throttle body, since the car was now getting more air from the new skunk manifold and tb the car was running lean i detunned the afc and the car runs fine. i acctually got my turbo today from ups with the emange so if it runs lean again i will have the shop tune the air fuel ratio through that