Audi A6 2Ltr TDi, surging at 1800 To 2000 Revs.

If you disconnect the E.G.R Valve, the engine runs perfectly.

I am not sure if the E.G.R Valve is faulty or if it is receiving the wrong signal.

Reluctant to fit a £300 part.

Our local Audi parts dealer have not heard of this problem or of any softwear updates.

Has anybody come across this fault before?

Thanks,
Ian