Anyone know of general guidelines to follow when tuning your vehicle as to not affect the factory warranty?

 

I'd like to know this as well. I have a pre-owned certified 03 Audi with the 6 year 100,000 mile warranty and was thinking about getting a chip for it at one point. I won't get a chip if it voids the warranty but I have no idea if it does or not. Anybody know what mods void warranty's?