IMPORTANT. My tuner just told me that if you try to change tunes while the engine is hot, it will fail every time. He said he had the same issue with his TT 5.0 and 2c5s roush. Gotta open the hood, let it cool, and then load the tune.
Total bullshit. I've changed and adjusted tuning on my sct at the track,after 10+ laps and drove the car there.
If you want to clear the cars ecu unhook the negative battery and turn on the lights. That discharges the brain box's charge that saves the programming.