I have an 06 A4 2.0T and recently noticed my check engine light was on and that my turbo wasn't kicking in. I took it to a local shop and they said it came back reading that it needed a turbo cutoff valve - which they also called a booster pressure sensor (I'm thinking it's either the same thing or the sensor is part of the valve part??). Anyone have any idea as to how hard these are to replace if I were to do it on my own?

 

They are not hard at all. The hardest part is getting ramps or jack stands in the right place.

You should buy the part 06H 145 710 D. There are several websites around the net that will have one. I got mine from genuineaudiparts.com (try searching under VW...for some reason they don't have it listed under Audi).

Crawl under the car and find the diverter valve with an electrical cable clipped to it and mounted with three 5 mm torx screws and pull it out. There are some DIY's that might help on this site or other forums like Audizine.