well i recently put the Pacesetter LT's and TSP ORY on my car. I also removed the EGR and AIR system from the car. I then had a guy in Washington who tunes F-bodies tune out the codes for the EGR, AIR, and the o2's. My SES light was off for about 2 days after getting tuned, then it came back on. IS it maybe a bad o2 sensor? Are there other typical things that throw codes after a header install? Please help. Thanx

 

Could be a missfire code. Have you checked to make sure all plug wires are good?

 

go to an Autozone if you have them, or get somebody w/ diagnostic tests to plug you in find the code, and post it up or look it up on here.

My guess would be a Bad Front 02 sensor, that seems fairly common w/ new header installs