Well, it stumped the Audi dealer, but a quick run on the dyno today revealed my lacklustre S4 to be producing only 227bhp and 245lbft, with a boost pressure of 0.3bar!!!
5 error codes in the ECU, and 3 months of piss poor performance later I am happy [img]/ubbthreads/images/graemlins/smile.gif[/img]
Faulty MAF diagnosed, warranty companies wallet bashed and its getting faster and faster as the ECU adapts back to full form.
We got 267bhp as the ECU was adapting, and if anything its got better since.
Moral: don't beleive a word Audi dealers say and trust your paranoia (its good for you, honest!)