A3 2.0 TDI Turbo Charger, Under Boost issues

[MSS3]

Hi All,
I'm new on this forum and have a A3 2.0 TDI 2009 year Sportback with the common rail diesel engine.
Whilst driving at higher speeds on the motorway for over a few miles my Glow plug light starts flashing,
I've had the cat plugged in and have been given a error code of P0299 with message of TURBO UNDER BOOST, Permanent.
Could any one please advise what I'm up against ? Some maybe Turbo others the Actuator and a few saying it could be the Turbo boost sensor?
Are there any good specialists in or around the Birmingham area please?

Cheers Manny,

 

[MSS3]

I've been informed that the Acutuator is faulty and that I need a new Turbo!

 

[NHN]

Yes but CR was only on facelift cars, so I would be chatting to audi about some form of warranty given facelift was only late 08 onwards, I think you may have some case.

 

[audicruiser]

I'd check all pipe work first as its quite common for boost leaks to occur at inter cooler joins etc...