Back of bus always dirty , is this just life with a DD?

[neoneddy]

Ammo sure it's not fuel? No. Not sure how I'd test for it. Power is good, in an earlier post I mentioned it seemed down for a while but it seems my throttle pedal  linkage had a bad bend in it.

Re: Dave, yeah it's always good to know something isnt for sure catistrophically failing. I lost my oil filler cap this spring and that was a mess. 

I should.also add I have a small exhaust leak near the turbo after the outlet. I also replaced my muffler and never added on a down pipe to the end. So it just exits the muffler and kind of back filled the engine bay a bit with smoke on those cold mornings.