I had to get a used wiring harness because the one that came with my engine was totally destroyed, and time to rewire and all that was too much. So I have enough wire to reach the connector, but i left the sensor off and it gave me a cel. I guess I can hook up the O2 heater and just mount it so it works but does nothing?? I am thinking this will cure the CEL, and I also want to pass emmisions, so other ways I have thought about may cause a problem once hooked in to the the emmissions test. I also dont have an a/f gauge, maybe it would be a good idea now. I am getting it tuned in about 2 weeks, and i am nervous as hell right now, havent' put more than half throttle, it boosts up quick, havent seen more than 15 psi, but i try to keep it at 0.