2007 Mk4 1800 tdci bought with a faulty turbo showed code 2663. Problem is now sorted, changed the complete turbo and electronic actuator, fitted one of a 2006 Focus (part numbers were identical lots are different!) Fairly straightforward DIY job with a reasonable set of sockets and spanners took me in total around 4 hours, that was including a lot of messing about with the top connector on refitting. You need access from above and beyond (ramps are good but a pain if its to high as there is a lot of climbing from bottom to top) i had mine up on blocks to allow enough space underneath and still access from above. Hardest part was on re-assembly getting the top pipe to clamp up tight ended up removing all the bottom fixings and attaching it to the top pipe first. I paid 150 including postage for the complete unit and did see a couple on ebay a bit cheaper. Reset the lights and car now running fine and turbo boosting well.
If anyone is encountering similar problems id recommend trying yourself before spending hundreds for a garage to do it, its well within the scope of a reasonable diy'er.
Tony