OK I have weird problems with my CEL lately and I'm not quite sure what's causing it so I want some opinions. First and foremost, I just removed my BBK off-road X-pipe and put my MAC off-road H-pipe back on, and I have BBK MIL eliminators which as far as I know work as they should. First question, does anyone know if an exhaust leak where the exhaust manifold meets the H-pipe would cause the CEL to light up? It doesn't have a gasket right now because it blew out and I haven't ordered a new one yet but I can't hear a noticeable leak so I don't know if that could be it. Also when I had the X-pipe on (for awhile no gasket there either, but again no noticeable exhaust leak) the CEL light would come on maybe for a few hours and then go off by itself eventually. Now I'm pretty sure it's related to my exhaust somewhere, so I've narrowed it down to either a leak at the head pipe, if that could cause it, bad O2 sensor(s), or maybe the MIL eliminators are just acting up. Anyone got any ideas?

 

Mine was doing that also when I changed midpipes and pullies. I think that the computer just had to adjust itself. It went on for a week or so regurlarly and the a couple times the next week. It hasen't came back on since.

I could be way off base here, but that's what my car did.