Technically anything that you do to your car will void the warranty in regards to what you have done. For example if you put springs on your car, your engine blows, your okay. But if you have a leaky damper, the dealership will not honor the warranty. In your warranty booklet is states that any modifications give the dealer the right to void warranty unless the part(s) are installed by a toyota dealership. When I first bought my 2001 gts, I missed a shift, over-revved, and bent two valves. It was hell trying to get toyota to honor my warranty because I had a cold-air Intake
and underdrive pulley kit. (Both AEM
, and legal) My suggestion is to replace the factory parts before bringing it in to be repaired or inspected.