Vag com seemed to cure my problem
I'm running a 2004 A4 1.8T 190 quattro. She's done about 60,000 miles and has started surging under hard acceleration. Whilst still in warranty it did this a bit, but when the stealer checked it out they reported on problems.
I've just got vag com 409 set up and connected tonight which reported no fault codes from the engine. So I went out for a spin whilst still connected and the car was perfect - no surging just good strong acceleration.
Anybody else experienced something like this i.e. problem solved simply by running a check?
I know it's too good to be true really.