I have a 2000 gt with 131,000 miles on it and just put a greyhound performance x-pipe, flowmaster cat back exhaust, and the mil eliminators...I put the original 02 sensors in the new x-pipe...put about 20 miles on it and now the check engine light is on. I've read that even with the mil eliminators on, sometimes the check engine light comes on or the 02 sensors go bad and when you replace the original 02 sensors the check engine light will stay off...first time on this web site...any ideas or advice...thanks for the help....