I have a 98' mustang GT with the 4.6L V-8 and the check engine light is on. First I thought it was the O2 sensors because I just put a Ford Racing catback kit on it, so I buy a set of BBK M.I.L. eliminators. Still the check engine light is on. Well I should also point out I have a Ford Racing 70mm throttle body, Ford Racing 9mm spark plug wires, MSD coil packs, and a K&N airfilter. So I take it to Autozone and have them scan the code for me and stupidly I for got to write down exactly what it was, I do remember it said something about the mass air meter. I am going to go back tomorow and have them read it again and write down exactly what it is. If anyone can help me out I would appreciate it.