I recently installed a 15% pulley and a couple days later I noticed my check engine light. Got it checked out ended up being a P0138. I believe it is because I'm running rich. Here is the list of mods. 15% SC Pulley Magnaflow cat-back exhaust Alta CAI Those are the only ones that would effect my engine. Should I get a tune to try and even me out a bit? I'm thinking about checking things out at Madness Motorworks. Any advice?
15% shouldn't cause you to run rich, first I would find someone to clear your adaptations so that the ecu has a chance to learn the new pulley from scratch, if that doesn't do it, more likely it is actually the O2 sensor itself.
Yep, what he said!! the pulley would more than likely 'lean' out a bit, do to the add'l boost. Could be now you are having a detonation issue and the knock sensor is doing what it was intended to do.. add fuel to save the engine! ( remember to drop a heat range on your spark plugs, when adding boost) Could be the MAP sensor! Could be the O2 sensor! Some one for sure will be on here to get deeper into this. Just me............................... Thumper PS: colder spark plug is the Autolite APP3923 and gap it at .035