The closest thing I've done on my car for a warranty claim is to pull my EGR valve tube and block it off, since I know one of my sensors are dead but my on board diag. computer didn't registered it, so I have to do it to get the proper code and to set off my CEL!
Plus, I take out my stoopid air filter everytime I bring it back to the dealer even though it's un-related repair. You'll never know if they marked down what kind of mods you got on your car. Next time they might turn you down because they "remembered"!