Exhaust Hiss???

[nitetime_pr]

Hey gang, got a problem with exhaust hiss at high rpms. My exhaust is a stock cat and pipe, Borla XS single in/out 2.25 muffler with an Ansa 2.25 resonated tip.

The low to mid rpms sound damn good (almost european sports car like) but when I give it hell, it sounds like it's hissing. Is this the result of blockage or too much back pressure? Might my stock cat be partially plugged up? Anyone else have this problem and fix it?

Any advice will be appreciated. At this time, I'm considering a new hi-flow cat or a test pipe. Any opinions one way or the other?

Thanks, it's nice to have a place to ask questions. Stay cool all...

[pace2006]

Re: Exhaust Hiss???

Mine used to do this when shifting under WOT. Kind of forgot about it, but now that I think about it, I haven't heard it since I took the car to the exhaust shop to weld up the Y-pipe after header install. I'm pretty sure it was from a broken weld right after the cat, which the shop welded up that day.

Although apparently part of that weld broke again just the other day, so I'll be listening for any noises under hard acceleration.

Check for any leaks or broken welds under the car. Usually a hiss is a sign of a leak.