Audi A4 2.5 TDI SE - EGR Valve

Fed-up with Audi. Have owned this UK car new since Dec 04, serviced by Audi during warranty and thereafter by Audi / VW independent. Car has covered only 18K but they are in the main monthly long distant motorway trips. Original EGR valve replaced July 08 (cost 393.00 GBP) after independent switched me in Dec 07 from standard VAG oil to Castrol and changed service cycle from 2 year to 1 yr service. He indicated that the VAG oil was clogging up TDI engines so best to change. EGR problems appears to have returned; engine management light ON and rough idle + smoking on accelerator pedal blip.

Should this be happening at this age and mileage?


Our other car bought at the same time (Mitsubishi Colt diesel) just does short trips and has not missed a beat.

Cheers
Steve :(