I have a 2001 VW 1.8t and my exhaust has the same smell that you decsribed. People told me that the rich smell was normal in a turbo, but now I have a lot of problems starting it up. When I turn the key, if I don't start it on the first try, it will take forever to crank up. After that the RPMs hit 3000 sometimes and stay for a minute or two. Sometimes the RPMs jump up and down and stall my engine out. All of these problems have black smoke coming out of my tailpipe when I'm experiencing them. Does anyone have an idea??????????? (everything has been tuned-up: sparkplugs, fuel filter, oil, coil-packs, air filter)