I hate to say it, but "chuff chuffing" sounds like a bad valve.

I mind less saying that I always have trouble getting the exhaust to seal
well, and that I now use high-temp silicone on both sides of the exhaust
gaskets (don't know the specs of the silicone, but it seems to take the
heat).  I also usually use the VW gaskets only as a template for making my
own.

Raymond

On 9/5/07, Jeff Stewart <fonman4277@comcast.net> wrote:
>
> <BTW, my brand-new exhaust system
> already looks like it's 4-5 years old, complete with a rusty tailpipe.
> What's up with that?>
>
> Pretty typical. I think the tailpipes start to rust in shipping. Unless
> you spring for stainless steel or take the parts somewhere and have them
> professionally coated, they rust in short order. You can always paint the
> parts with Rustoluem BBQ paint-that lasts about 2 weeks.     Jeff
>