well, the mechanic is partly right.
- a code is set saying the car has been tuned
- you can always install the backup, and make sure the code is cleared before taking it in
- it wont void your warranty IF it has nothing to do with the problem at hand... for instance:
a U-joint breaks and your driveshaft shoot through your floorboard. they cant say "sorry, you tuned your car, we arent covering this." there was actually a law that was passed called the Magnusson-Moss Warranty- Federal Trade commission Improvement Act of 1975 that protects vehicle owners from the dealer fraud. so if you have a problem, tell them to research the law and then tell them when you need your car back. good luck and hope this helps.
