i've got this problem with my A6. I've got a code P7401 (tourque converter-TC, circuit clutch or stuck off), i have reset it and it comes back after 3-4 days. There is no change in the driving performance of the car, or maybe little bit a slower response. I don't think i need to change the TC, cause if TC is bad it's gonna be bad all the time. Or maybe i am wrong. Any help on this?

I was havng the same problem with my car, espically when it downshifted into first. I took it to my mechanic and he said right away that it was the valve body and that this was common in some audis, including the A6. Have someone check out your trans valve body, theres a small needle in there that pulls in and out and if its not moving correctly, your shifts will be rough.
Hope this helps...

If you have a torque converter fault there is no getting around it, it has to be replaced. It can make problems with the transmission intermintently and it will cause a check engine light as well as make you fail emmissions.

Thanks, if the flush and filter change dont fix it by monday, then I will surely have someone take a look at that, thanks alot for your help

Did the flush and filter change take care of the problem???

It did for a little bit, it seems like its coming back [:@]