That's exactly what they are saying.That I have to cover the expenses because of the mod. that's why I want to know if it's something for a DIYer.

And me, too. 01 225 Coupe. No mods. Two weeks ago the light went on for four days. I scheduled a maintenance, but it went off before I got it in the shop. I was told that if the light went off that there was nothing they could tell me. Sounds like I wasn't told the whole story.

00 180hp >>I took in my car today to Audi dealership in Pasadena bcuz of the similar problems my car had with yours. MY check engine sign was off and never turn on but since my MAF was under waranty I decided to take it in to AUDI.I whent in to see if they could replace my MAF sensor but the technician said that they had to run some diagnostic check first and after spending 6 hours on my car they said that there were three problems with my car:1)Needed a secondary air pump $550 (2) New BOV valve $280 and something else. To make it worse they told me that this might not fix my problem for sure but it was a good start. I decline any more work to be done on my car because Audi mecanic were just fishing at my problem and still had to pay $125 for their diagnostic. I bought the MAF sensor after and installed it in 10 minutes and guess what my engine problem was GONE!!!! Thanx Guys

Full1effect how hard was it to intsall the sensor and how much did it cost? Also where did you buy it from?

I bought it at the Audi Part Department for $82 dollars and it took me like 5 minutes to install. All of the intallation information was obtain from reading Audi TT Discussion Forums.