ok so i wanna get a cat back exhaust really bad but my service guy said it will void my warranty.. so i was wondering if i got a cat back exhaust and put it on and when i have to get my car serviced i put the stock one back on will they be able to tell i messed around with the exhaust and stuff??

 

They'll see tooling marks on the bolts at the cat and your O2 sensor. Shouldn't void your powertrain just for a catback though. I'd go to a different dealer.

 

My guess is that they won't be able to tell if you're somewhat careful. But not all dealerships will void a warranty for a catback. Fresno Mitsubishi, for example, will allow an exhaust. Things which will automatically void a warranty are a MBC, intake, tune, cams, etc. Just ask your dealer.