Per my post below, I called the service manager to politely ask about the 135 miles placed on the car during its recent week long service. He told me that the car was road tested more than the two times indicated on the receipt because that had a hard time figuring out the problem. The diagnostic procedure went something like this:

Friday May 28 - I took the car in for an engine fault showing a lean fuel mixture on both banks. After running the diagnostic with their own tool, they followed the standard diagnostic process and find nothing. They called the Audi Service Hotline and talked to a rep who gives them a lengthy additional checklist apparently involving numerous road tests.

Tuesday June 1 - They continued testing the car into Wednesday based on the Friday Hotline call and still found nothing.

Wednesday June 2 - They again called the Audi Service Hotline to get further guidance and get another guy who listens to the symptoms and says "Yeah, we've seen that 17 times now with the D3 A8 4.2. Just replace the air filter element and make sure the seals are fastened correctly." Of course, they must order the air filter element which would be their overnight.

Thursday June 3 - They replaced the filter element and road tested the car lots more. Voila! Problem solved.

So, what created the problem, you may ask? According to the service manager, they caused the problem during my 5,000 mile oil change. The air filter box containing the air filter element must be moved out of the way to get to the oil filter. When they moved the air filter box back into place, they did not verify that it was sealed correctly (it was not) allowing air to blow by the filter element which confused the engine control computer. The service manager also said that mine was the first D3 A8L with sufficient miles to get the 5000 mile service making me the service departments' guinea pig. Oh joy!, given that I put 18,000 miles a year on a car.

Lastly, the service manager apologized for giving me a Jetta loaner. He told me that the General Manager ripped him a new one for not giving me an Audi loaner after I sent them my 7-page piss-and-moan letter detailing my this incident as well as my service history with these guys. I guess the GM really read my letter!

Seems like the tribal knowledge isn't being shared. After 10 or so of these, you'd think a TSB would be appropriate. It sure would have saved a whole lot of aggravation.

It's good to hear that they gave you an explanation and that your car is on the road again. I guess my taking more than 7 months to reach 5K miles had a at least one benefit :-)

I'm sure you'll have your SA prep the service department prior to bringing in your car for the 15K LOL!

I'll make sure to have them verify that the air filter is reinstalled correctly. Glad to hear that the dealer could explain the high mileage and document the service process. I just hope my car wont be a guinea pig during it's upcoming oil change.