This is a quote from a different thread, the thread can be found here:
stillen intakes and fast intentions cbe tune?
I am 100% aware of this, BUT, the information I spread is NOT false info... If you're saying your aftermarket radio controls your speakers, and if the speakers give out, YOUR modification caused caused the defect... The ECU controls the engine... Pushing it or modifying it outside of the factory specs, ANY tuning is considered "outside" the factory specs, because if the stock ECU notices anything it cannot correct by itself due to your mods, it will throw a CEL, kinda the reason behind a CEL...
When people ask what mods effect warranty I explain whatever you had to touch to install that mod, usually loses it's warranty (On intakes you'll usually lose the warranty on MAF sensors, on HFCs you'll lose the warranty on the O2 sensors)
No, you do not lose the warranty on the WHOLE car, I didn't say that, I just said at LEAST the engine... They can claim more parts are out of warranty (reason stated below) But yeah, you can have a different engine in your car, they'll still fix your window as long as you're under some type of warranty on that.
On the alternator, you're in a gray area, I bet my money that corporate wouldn't replace it willingly, they will say you over worked the alternator and the belt snapped due to it spinning too fast, and you not keeping the car maintained by having the belt replaced...
The gray area is here... If you take your car into the dealer, they'll most likely go shite the belt is gone, if you're within the recommended 30k service interval for it they'll replace the belt, THEN if you go in and they check that the alternator doesn't produce any electricity, you'll get your new alternator, I agree, but when the repair is for something small like that, the dealer isn't going to type in every mod you have and how the engine is tuned, if it has a tune, and how high the redline is, and how often you do your oil changes, and if you have good tread on your tires into their system when they go to file a claim with corporate... And it's not a huge blip in the system when a $1000 total repair is called out. (I had my seat replaced on my maxima twice [$3000 as noted on the invoice] each time, as well as 2 struts, 3 window motors, and 3 window regulators and a motor mount. My instrument cluster was changed on my 370Z, $800, plus 10 days of a car rental)
The only mod I know of that can't really effect your warranty in any way is a CBE (even though it kinda clashes with the other info I've posted below)
Also, the other beautiful advantage Nissan has, is that they can say, even on my car that has full breather mods, 'because my car has more horsepower than stock, I put extra stress and strain on the engine and transmission and anything really related to the drivetrain'. Now, if I have catastrophic failure, you best bet your arse that I'm reverting to stock, but when you revert your ECU back to stock, they WILL KNOW that. (Same with things like the MAF sensor, they can say I overworked it, or I overworked the O2 sensors or they got too fouled because the HFCs aren't as efficient as stock cats)
And if a STATE can tell how many times you flashed your ECU and they won't pass your car for inspection, what makes you think corporate, who has to shell out THOUSANDS of dollars, won't do the same, and deny a warranty claim?