[bclark89]

Hello all

I drive an '03 Pontiac Sunfire. I got this car very cheap as a repo and it is great. My only concern is the ridiculously large tuner car type replacement muffler that came on the car. I've been told that this causes low backpressure and that cold air can work its way all the way up the exhaust to the valvetrain and cause damage such as bending valves, breaking springs, etc. As far as I can tell the rest of the exhaust is stock and the cat converter is present. Does the full length tube and cat create enough backpressure to protect my valvetrain? I realize every car is different but I'm wondering if anyone has encountered a similar situation or heard about one.