Hi all,

As you know, our 997TT has this mild "rattling" noise from the belt tensioner area. This noise is getting louder.

HAs anyone encountered this problem before? Is it due to the bearing?

Tks,
Ron

I just had one replaced on my 996TT. The part was $200 and an easy fix.

i had rattling in the catalysts before (broken cat) in my 997S, but noises (yet) like that in my 997TT.

Will a broken cat affect the performance output in anyway? Was the cat from aftermarket exhaust?

If a cat goes bad it can clog and affect performance.

I'm not sure if the rattling cats affected performance, I assume so as it would probably restrict the exhaust. After they were replaced, I cut them apart. Both of the "honeycombs" were loose and freely moved around inside the metal structure. I'm not sure how they got loose, but I believe someone said it could be because of heat - either a lean or too rich mixture condition..????