Many people have asked whether or not the use of aftermarket parts, including performance chips, affects the new automobile warranty. Well, I did some research into this and came up with an answer. Many people already know the answer, but might not know exactly where to find it in the laws. Other people don't know the answer at all. Hopefully, what I've written will be helpful to everyone.

On July 4, 1975 the Magnuson-Moss Act, enacted by Congress six months earlier, went into effect. It is part of the official United States Code and can be found at 15 U.S.C. 2301 et. seq. Section 2302(c) specifically addresses the issue that most people on this board are concerned with. In pertinent part it states:

"No warrantor of a consumer product may condition his written or implied warranty of such product on the consumer's using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty) which is identified by brand, trade, or corporate name. . . . 15 U.S.C. 2302(c)."

Additionally, Congress supplemented this Act in 1977 when it interpreted the Magnuson-Moss act. This interpretation appears at 16 C.F.R. 700.10 section 102(c) and states, in pertinent part:

"No warrantor may condition the continued validity of a warranty on the use of only authorized repair service and/or authorized replacement parts for non-warranty service and maintenance. For example, provisions such as, 'This warranty is void if service is performed by anyone other than an authorized "ABC" dealer and all replacement parts must be genuine "ABC" parts,' and the like, are prohibited where the service or parts are not covered by the warranty. These provisions violate the Act in two ways. First, they violate the section 102 (c) ban against tying arrangements. Second, such provisions are deceptive under section 110 of the Act, because a warrantor cannot, as a matter of law, avoid liability under a written warranty where a defect is unrelated to the use by a consumer of "unauthorized" articles or service. This does not preclude a warrantor from expressly excluding liability for defects or damage caused by such "unauthorized" articles or service; nor does it preclude the warrantor from denying liability where the warrantor can demonstrate that the defect or damage was so caused."

Therefore, under the laws of the United States an automobile warranty is only inapplicable if the manufacturer proves that the aftermarket part was the cause of the defect/damage. This is important, because it places the burden of proof on the manufacturer. Thus, the consumer is under no obligation to show that the aftermarket part did not cause the defect/damage.

Unfortunately, I was unable to find any court cases dealing specifically with the issues that many of you are concerned with. The only two cases I did find were an EPA/clean air case and a defective aftermarket part case. In the EPA case the issue related to the Clean Air Act and the implementation of programs by the EPA. The second case involved an aftermarket air conditioning unit that failed. In this case the court held that the automobile manufacturer's warranty did not extend to cover the aftermarket part used when the aftermarket part fails.