Hey, I just bought a 98 talon tsi with 60,000. The car had been running good for the first couple weeks, but now at idle it seems to be running very rich, as I can smell fuel, while sitting in the cab, and the car is idling. The car is completely stock except for a k&n filter and a small filter off the pcv. I have read on forums that it could be 02 sensors, maf, or fuel pressure regulator. I really don't want to replace all these parts as trial and error if there is a test i can do to isolate the problem.