Hello, I have recently purchased an audi a4 2.0 tdi Quattro 170bhp, 2007, with a BRD engine, I have had this issue since purchased, when accelarating either on motorway or elsewhere! The glow plug light comes on and loses power, and now there is not much power when driving, since reading these forums, thought it could be egr pipe etc, I have taken this to a garage who have given me two codes, po299-obd and 00665 -vag and say boost pressure regulation reached? I'm no mechanic but they have recommended refurb the turbo? If I go ahead is there other items that can be sorted out like the egr etc, cleaned? So no need to keep taking it back. Hope you can help, I would be grateful. Thank you.