Just put an O/R exhaust on my 07 GT. Have read on here where I can expect a check engine light in about 100 miles. I have read guys say you have to turn off the rear O2 sensors. Great... How do I turn them off? can it be done from inside the car somehow (like seatbelt warn. chimes)? Do I need to get a tuner to do it? If so what kind? Or do I have to take it to a shop? Any Help would be greatly appreciated.