It has come to my attention that people are a bit confused on what a dealer, or manufacturer can and can not void a warranty on. A dealer can not void a Warranty unless they can prove that the aftermarket part caused the failure (They can not just simply say because you added this or changed this for that it caused the failure).
Here is some good info that I have dug up
"Do I have to use the dealer for repairs and maintenance to keep my warranty in effect?
No. An independent mechanic, a retail chain shop, or even you yourself can do routine maintenance and repairs on your vehicle. In fact, the Magnuson-Moss Warranty Act, which is enforced by the FTC, makes it illegal for manufacturers or dealers to claim that your warranty is void or to deny coverage under your warranty simply because someone other than the dealer did the work. That said, there may be certain situations where a repair may not be covered. For example, if you or your mechanic replaced a belt improperly and your engine is damaged as a result, your manufacturer or dealer may deny responsibility for fixing the engine under the warranty. However, according to the FTC, the manufacturer or dealer must be able to demonstrate that it was the improper belt replacement — rather than some other defect — that caused the damage to your engine. The warranty would still be in effect for other parts of your car.
Will using 'aftermarket' or recycled parts void my warranty?
No. An 'aftermarket' part is a part made by a company other than the vehicle manufacturer or the original equipment manufacturer. A 'recycled' part is a part that was made for and installed in a new vehicle by the manufacturer or the original equipment manufacturer, and later removed from the vehicle and made available for resale or reuse. Simply using an aftermarket or recycled part does not void your warranty. The Magnuson-Moss Warranty Act makes it illegal for companies to void your warranty or deny coverage under the warranty simply because you used an aftermarket or recycled part. Still, if it turns out that the aftermarket or recycled part was itself defective or wasn't installed correctly, and it causes damage to another part that is covered under the warranty, the manufacturer or dealer has the right to deny coverage for that part and charge you for any repairs. The FTC says the manufacturer or dealer must show that the aftermarket or recycled part caused the need for repairs before denying warranty coverage." source- http://www.consumer.ftc.gov/articles...ne-maintenance
"In a Consumer Alert issued by the Federal Trade Commission (FTC), the agency confirmed that “The Magnuson-Moss Warranty Act makes it illegal for companies to void your warranty or deny coverage under the warranty simply because you used an aftermarket part.” The alert outlines key provisions in the law that provides protections to car owners. As defined by the FTC, an “aftermarket' part is a part made by a company other than the vehicle manufacturer or the original equipment manufacturer.”
“The FTC’s reference to aftermarket parts is equally applicable to specialty parts,” said Russ Deane, SEMA’s General Counsel. “Under the Magnuson-Moss Warranty Act, the warranty cannot be conditioned to a specific brand of parts, services or vehicle modifications unless those parts or services are provided free of charge.”
The alert notes that a consumer has the right to patronize independent retail stores and repair shops for parts and service without fear of voiding the new car warranty. The dealer/vehicle manufacturer has the right to deny a warranty repair but they must demonstrate that the aftermarket part caused the problem. The warranty remains in effect for all other covered parts.
The FTC alert may be downloaded using this link: http://www.ftc.gov/bcp/edu/pubs/cons...ts/alt192.shtm
The alert was issued in response to an FTC complaint filed last August by the Automotive Aftermarket Industry Association (AAIA), Automotive Oil Change Association (AOCA) and the Tire Industry Association (TIA)." source - http://www.sema.org/sema-enews/2011/...ermarket-parts
some additional reading from the FTC can also be found here. http://www.business.ftc.gov/document...l-warranty-law
Hope this helps clean up confusion. And about tuners I have personally had a service tech at chrylser look at my computer without a tune on after one had been on there and he could see nothing had been there except the factory tune, and then I flashed the PCM, and he could indeed see the tune, then reflashed it to stock and he could see nothing again, I have done this on a 2012 Ram, and a 2013 Challenger, the only thing he could see was the access counter had been raised, which is done every time the computer is accessed for anything weather it is to check for a code, clear a code, dealer reflash for a new radio or whatever so it can get up there pretty quick within reason. It should be noted these tests were done with a Trinity t1000, and are my experiences with my dealer, other here on the boards have reported similar findings as well.
It should also be noted that it is HIGHLY recommended that any time you go in for service if you are running a tuner to reflash the PCM to factory and remove the tuner from the vehicle.