I ordered a F/W's header,flex-pipe,stealth muffler, & 1 of their X3 flasher's, w/ EGR delete, rear oxygen sensor disabled, & 1 of their custom programing was a early fan activation. My car has 3 02 sensor's now, does the rear oxygen sensor disabled, delete the 2 rear sensor's? I beleive the 1st is to run the motor & the 2nd one is to monitor the converter, & the 3rd one, I don't know? Thanx again for your help!