Hi, welcome to JA. Can you tell me what engine size your A6 is equpped with? I can get you an exact amount if you can get the labor rate of the shop, otherwise I'll give you a range for parts and labor. If you can provide the diagnostic code they pulled from the enigne ecu, I can tell you if they're heading in the right direction with this diagnosis as well.
There closed right now but I'll have for you tomorrow.
No problem, also please post the engine size and I can start getting you an idea of how much this may be. Thanks.