I have a 92' Audi 100, obviously, and the exhaust is very loud especially above 2,000 RPMs. There doesn't seem to be a leak, I've been told it's just "noisy catalytic converters." I've also heard that the "cat's" may be partially clogged.
Has anyone else experienced this? Do I need to replace the catalytic converters to fix the problem? Any advice would be appreciated!
Thanks alot,
-Matt

 

Could be a blown gasket at one of the joints or a crack on the top side where it is less visible. A far worst possibility is a crack in the exhaust manifold.