[foosh]

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 nor does it preclude the warrantor from denying liability where the warrantor can demonstrate that the defect or damage was so caused.

This clause is vague, as is most legislative language, which is why we have such an active courts system and why we're still fighting about the meaning of the U.S. Constitution in the Supreme Court.

It does not state that the warrantor must prove beyond all reasonable scientific doubt that an aftermarket ECU reprogram caused a bent valve in YOUR particular engine. That would be impossible. All the manufacturer must demonstrate is that the ECU modification changed the performance parameters of the engine from the stock configuration, and that could have led to more wear, and ultimately a higher likelihood of failure in the type of engine in question. They have more than ample data to show given all their performance testing. In that regard, the tuners help make the case for the manufacturer in their claims of higher HP and torque, and that's all a manufacturer needs to win a case against you under M-M, involving an engine mod.

Moreover, it is against U.S. law to modify engine parameters because of EPA emissions certification regulations, and 99% of judges would bang the gavel and tell you to go home because you illegally modified your engine. M-M was passed into law years ago because certain manufacturers were trying to deny warranty claims for the use of non-factory aftermarket parts such as mufflers and air cleaners. It was designed to prevent manufacturers from having a monopoly on repairs and parts sales.