I have had my 09 Audi A4 since October last year. Put on a some stainless steal exhaust tips that I bought from ebay. Since then, the exhaust tips are completely coated with carbon residue. The original tips are completely black.
I was comparing them to my buddy's tuned '02 S4, the tips look the same as his. And his is 7 years old, mine is hardly 10 months old. My buddy told me that the gas to air ratio is set pretty high, that I am burning more fuel than needed for my use. Talk to the dealer and get them to check it out. I talked to the dealer, they said that this is a common problem with most audi's. So I want to put that out the this forum, do you this problem?

Cheers,
AP

 

yes, this is normal....