Originally Posted by
97mustanggton18s
I had the codes read. Theres one with something with the egr and one for o2 sensors. But those have been on for like a year. When My chip is on they arent so thats the only reason why they arent on now. I took my chip out to see if my chip was screwing things up.
Bingo,.. The engine can run strictly off the MAF and TPS with out getting any signal from the O2's. How ever,.. the MAF can only compensate for so much. At high RPM it will break up because of the lack of an O2 signal. The computer uses signals from the O2's to control the ignition advance (among other things). Not the only thing to effect it,.. but having had a similar issue in a GT that I converted to a DOHC motor,.. I think this is your problem. I had high RPM break up at anything over 4500 rpm. Even with my foot matted to the floor. Supposed to not matter at WOT,.. but it went away after I got the O2's to send the compter a signal.
Advanced Auto will pull codes for free. By what you described to me,.. I'm willing to bet cleaning your MAF wires and finding out what is wrong with your O2's will fix your problem.
Hurst