I have my inspectors license. My buddy has an 06 gt with a couple of mods and an sct tune. with the tune and the high flow cats, the MIL kept coming on for rear O2 codes, so we turned them off. I have inspected this car for the past 3 years this way no problem. This year, I got it to pass by never turning the car off. I had him pull up to the bay, I hopped in, and let it idle. the machine tells you to turn the car off for 15 seconds, don't do it. I believe that is the secret. Let it idle the whole time and it should be ok, at least it worked for us and his rear O2's are turned off.