Came across this while window shopping on Turnermotorsport.com. Some really good info that may clear some things up and help some folks. Obviously this only applies to those in the States, but there may be similar laws elsewhere. Here is what was on the site:
Generally speaking, a car manufacturer cannot legally void your warranty for adding non-stock equipment. The only circumstance under which the vehicle manufacturer can void the warranties is if an aftermarket part is responsible for the warranty claim. On the website,
www.enjoythedrive.com, there is an entire section devoted to the issue of warranty. There is a wealth of information there that can help you get your warranty issues resolved. Besides the federal laws discussed there, your state may grant you other rights under state law.
Also check out the SEMA website at
www.semasan.com and "A Businessperson's Guide to Federal Warranty Law" on the Federal Trade Commission's website for more information.
Federal Warranty Laws
1. The Magnuson-Moss Warranty Act (15 U.S.C. 2302(C))
This federal law regulates warranties for the protection of consumers. The essence of this law concerning aftermarket auto parts is that a vehicle manufacturer may not condition a written or implied warranty on the consumers using parts or services which are identified by brand, trade, or corporate name (such as the vehicle makers brand) unless the parts or service are provided free of charge. The law means that the use of an aftermarket part alone is not cause for denying the warranty. However, the law's protection does not extend to aftermarket parts in situations where such parts actually caused the damage being claimed under the warranty. Further, consumers are advised to be aware of any specific terms or conditions stated in the warranty which may result in its being voided. The law states in relevant part:
“No warrantor of a consumer product may condition his written or implied warranty of such product on the consumers using, in connection with such product, any article or service (other than article or service provided without charge under the terms of thewarranty) which is identified by brand, trade or corporate name....” (15 U.S.C. 2302(C)).
2. Clean Air Act Warranty Provisions (42 U.S.C. S 7541 (C) (3) (B))
The federal Clean Air Act requires vehicle makers to provide two emissions-related warranties -- a production warranty and a performance warranty. Theproduction warranty requires the vehicle maker to warrant that the vehicle is designed, built and equipped so that it conforms with emissions requirements at the time of sale. The performance warranty requires the vehicle maker to warrant that the vehicle will comply with applicable emissions requirements as tested under state vehicle emissions inspection programs for the warranty periods specified in the law (for model year 1995 and later vehicles, thewarranty is 2 years/24,000 miles for all emissions-related parts and 8 years/80,000 miles for the catalytic converter, electronic emissions control unit and on-board diagnostic device). The performance warranty is conditioned on the vehicle being properly maintained and operated.
Like the Magnuson-Moss Act, vehicle manufacturers may not refusewarranty repairs under the Clean Air Acts performance and defect warranties merely because aftermarket parts have been installed on the vehicle. The only circumstance under which the vehicle manufacturer can void the emissions warranties is if an aftermarket part is responsible for (causes) the warrantyclaim.