[crank182]

Is your car knocking when it is under load? I had a similar problem with mine. It changed a whole bunch of stuff and couldn't figure it out. I took it to an awesome mechanic and he had a complete scanning system. It ended up being the MAF sensor. It was brand new because the old one was broken but it had packing grease on it causing it to run lean. The O2 sensors were all over the place and the computer ended up advancing the timing a whole lot. He said that K+N airfilters can also leave an oily residue on the connectors of the MAF and it is a pretty common problem when using them. A little electrical connector cleaner did the trick and it was fixed in a few minutes. I never thought of that but it was that simple. Don't use break cleaner or anything like that on the MAF because it will most likely fry those little sensors. Hope this helps.