No aftermarket part or accessory that is properly installed on your vehicle will entirely void your original vehicle manufacturers warranty. According to the provisions in the Magnuson-Moss Warranty - Federal Trade Commission Improvement Act, It is the dealership's responsibility to prove that your modification directly caused or affected the failure you are trying to resolve. With that said, some dealerships are more performance-oriented than others and are more willing to work with customers.

Warranty-related materials, published by the new vehicle manufacturers, state that the installation of aftermarket parts have no effect on the warranty unless such equipment causes the problem that leads to the warranty claim. Nonetheless, some dealers have improperly denied warranty claims even though the claim had nothing to do with aftermarket parts. I.E., just because you install an exhaust system, your suspension failure warranty claim cannot be denied. If you experience a problem with an uncooperative dealership, point out the provisions of the this "FEDERAL ACT". For more information call your vehicle manufacturer or click on the link above to go directly to the Federal Trade Commission's website to find out more about this law.