Originally posted by BrApple:

drop in gas milage is because of the CEL, so getting mil eliminators to turn the CEL off will improve gas milage, headers could but not if you have a heavy right foot and like how your car sounds at WOT



Originally posted by projectsho89:

FWIW, the cat efficiency codes won't cause the PCM to go into any mode that uses more fuel.....

Steve




so which is it?

99 SVT Black/Midnight 1462 out 2760