Malfunction Indicator Light
 

Hey guys, I need some help on this one:

I have a 2000 Audi TT quattro, and my MIL has been on for about the last 6 months. Car runs great, no issues at all. Searched around online for causes why the light would be on and found a couple hits saying the gas cap might be loose. It felt a bit loose so I replaced it, but the light still hasnt gone off.

I live about 150km from the nearest dealership, so taking it in to get checked is a big trip.

I have a couple theories about the problem. Im thinking I might have a bad sensor, dirty condensation tank or that I might need to replace my catalytic converter.

Anybody else ever had this problem or have any other thoughts on why it might be doing this?