Question???
 

So I'm about to bring my car to dealer for oil change but I hv after market cat back exhaust on. Should I install the stock back on or just leave it? Is the dealer gonna say anything about it even though I just bring the car for oil change? please don't yell at me if this is a stupid question. Thanks.

I have an SRT Header Back Exhaust with an air intake and Crank Pulley. I Took it to my Toyota Dealer for an oil change no questions asked, and they even completed me on my exhaust. When they gave me my inspection paper, it just said aftermarket exhaust installed, so they did not check my exhaust for any issues, thats it. It depends on your dealer, but I have noticed the dealers near bigger cities are bigger sticklers for that kind of stuff.. Just my two cents, it should be no problem..hope it works out for you...

Maintenance is not warranty work, even if you're going in for the free oil change through the scion boost program. It would be very stupid of them to deny you service because of the exhaust.

In most states replacing a DOT approved exhaust with another isn't cause for denial of warranty. If were a header back system they may have cause to deny you. it falls under the "manufacturer can't require you to use oem parts" guideline. Usually if you navigate to your State's DMV page you can review that, I also think there's a thread here somewhere with links if you search.