I changed my h-pipe to my stock setup so i can get emmisions, now, after i drive for like 10 mins my ce light stays on. I also removed my mass air, so i dont know what i could have done, eaitehr the 02's or the massair i bet, both are new. only thing i noticed was that the o2's, one had a dent in the side i can"t remember if this is normal, also can you clean 02's? what could i have fugged up when i switched pipes....also i have no exhaust leaks. im gonna try and clean my mass air, connections etc and and rule out the intake....see my problem is i gotta get an inspection b4 i switch my h-pipe again and if he sees the ce light, or it makes the car run wierd(emmisions wwise) it wont pass... also the car is running Great...better than ever...so i dunno anyone help?