i was wondering if i move my catalic converter back down the exaust, and move all my O2 sensors becouse i have a OBDII car, will it make my car run rich or lean most of the time, or would it affect it at all? becouse its right in front of the manifold, and i just wanted to get a 1 piece header intead of header,cat, header second part, flexpipe, etc. well im just courious hope you can understand these question. I confused my self