i have banks exhaust street and performance intake and i had an edge programmer every now and then it would throw the check engine light and i would check it with the programmer and it said bank one lean well i recently sold the edge so im back to factory tuning but still have the intake and exhaust well on the way home today it threw up the check engine light so im sure its the bank one lean again but how can i make the light go out?? thanks

 

If you have a 5.4 they are notorious for running lean with aftermarket intakes.

 

Well... from prior experience with K&N CAI intakes, they tend to run lean, like Stealth said, because of the extra air flowing in. The MAF for some reason cannot compensate for it, and then the ECU throws a CEL. From what I've heard, *sometimes* unhooking the battery for an hour or overnight to reset the computer so it will "relearn" it's fuel trim strategy will work and keep that light from coming back on. Then again, something might have fouled your MAF sensor, as it is only a thin wire transistor and it's VERY sensitive to things like oil, something in which the K&N uses as it's filtering medium. Not quite sure on the Banks CAI... but the K&N does use oil to filter the air. The only other thing is put the factory air intake on and see what goes on, but of course clear out the engine codes and drive around and see if it will come back on. If it comes back on with the factory intake, there is something wrong with the MAF sensor or possibly something even worse.

I had a CAI on my '03 Escape, and it threw a CEL with the same issue you are having with 1 bank being lean. I then reset the code, and threw the original air intake on and voila, drove 500 miles without a code. So I thought it was fluke, and I put the CAI back on, and drove not even 50 miles, and that pesky CEL with the 1 bank being lean. Then again, I've had a K&N CAI on my 2000 Dakota, and never had an issue.

So, it's hit or miss...