Don't know much about the tuners, but if the dealer can detect something has been altered, they sure can void your warranty. Now if you can get something that doesn't leave a "footprint", you may be ok. My .02, don't waste your money......seems like everything I've owned in the past that I've done performance mods something has went wrong and I always wonder if it would have happened without the extra power. A buddy of mine had a Cummins with some stuff done to it...ran great and when he kept his foot out of it, it got 23-24 mpg. But I can tell ya he never saved any money with the chip cause there was ALOT of unburned diesel rolling outta the 6" pipe!