5 star said that even if you remove it before going to the dealer the PCM will retain the history and in any major warranty claim the first thing ford does is download the tune history. They did say if you drive it 50 to 100 miles it will reset the history, but this would be hard to do if your tranny or engine is down. They did say that even if it resets and it gets past the dealer that on major claims ford will have the dealer send the PCM to them and they can still read the history. They say Mustangs are the biggest abusers,
P.S Mccsix I like your profile pic, I am just about finished restoring a 28 tudor that my Great Grandpa purchased new. Need to install the top and blast and paint the wheels.