My Car is Running Rich?

Bought an '01 Jetta Wolfsburg (1.8 turbo) three weeks ago from a VW dealership. Today the check engine light came on, indicating that the system is running too rich. Likewise, the tips of my tailpipes are both black and there is a strong smell of gasoline coming out from under the oil cap. I'm bringing it to the dealership on Monday, expecting to hear the run around. Anyone have any guesses what could be going on here?