I am looking at a 2006 A4 2.0 Turbo from a private seller. The "check engine" light is on. He says it's the gas cap connection to the computer. Any insight to this?

I am always suspicious of sellers who say "it just needs this one little thing fixed". If it is so easy why didn't they take care of it?

Thanks all! I will start with the easiest detective work (auto parts store scan for codes), then call the dealership with the Vin # to see what they will share about the car and this on-going issue.

Carfax too.