OBX Long tubes with 02 sensor CEL
So i recently installed OBX longtube headers with the H-pipe. From the axle back i have magnaflows. The headers had threaded holes just where the rear O2 sensors were, so that's where I screwed em in. There were no ports for the O2 sensors closer to the engine.
I also have the SCT X3 tuner, and had them give me specific tunes for my exhaust setup. The CEL clears right after I install the tunes, but the moment i restart the car, it comes back.
I know the rear bank of O2 sensors measure the CAT efficiency, but now that I don't have CATs, is this what is causing the problem? Am i getting the CEL because I just don't have the front bank installed on anything? What do I need to do get rid of this trouble code?
I've read some forums say it might be my fuel pump, or it might be an exhaust leak. With no CAT's, and no resonators, I can't hear or smell for any leaks under the thing...any suggestions?