I have been noticing that the carbon has been building up in my exhaust tips. My car isn't using any oil, I'm running Doug's 91 performance tune and I only have 8100 miles on the car. Attached are some pictures so you can see for yourself.

 

It is running rich with the tune. It is a safety margin- mine does it on the stock tune. No worries besides cleaning.

 

yeah, I notice that a lot...
it sticks to the borla tips (rolled) really well...
and it's annoying

 

mine are black.

 

It's normal...Our car's will always run a little rich at start up and idle etc. If you didn't have a little soot build-up in your tail pipes it would be time to worry.

 

Thanks for the replies. I thought that was the case but wanted to get expert opinions. A little rich is always better than a little lean.