i started noticing when i get hard on the gas my exhaust sounds almost hollow? almost like an aluminum can kind of howl. could it be an exaust leek somewhere?

 

never driven a 2.8 but all audi exhausts are relatively quiet except for the V8s (which i am envious of)

 

it just sounds wrong? not sure how to explain it really. then again maybe it is my exhaust manifold? hmmm. who has a 2.8 with stock exaust?

 

I did and i remember it vividly, i now have the center resonater and rear mufflers sitting in my garrage though. Could you post a sound clip of it or a video so i could listen to it?

 

probably a little leak somewhere. should take it to exhaust shop before it gets worse

 

could be the cats

 

I once made the mistake of putting NAPA exhaust hangers on my 1996 Audi A6 Quattro 2.8L and all three of them broke, causing a grinding noise when accelerating. You could have broken exhaust manifold studs or bolts at high mileage. I used some 5/16" stainless steel bolts, which are almost 8mm for my exhaust. For studs, you can use an 8mm die on one end and a 5/16" die on the other end. You can also order metric stainless steel bolts, however the 5/16" stainless steel bolts are more common at local stores. You may order almost any stainless steel bolt from:
www.mcmaster.com/

 

I heard something similar in May and couldn't find a leak. When I rapped on the cats, I found that the guts were loose in one and really loose in the other. Replacing the two cats was one giant pain.