Right, so have had my 05 GT JTD for about 9 months now, my first Alfa, delighted with it and pah to all those mates of mine who are BMW bores who tell me to get a beemer. Touchwood, EGR problem aside, it's been 100% reliable too.
So had the problem, a load of smoke under acceleration, enough to cause those behind to flash me (lol) and poor pick up of the engine and finally motor control unit failure last week, flashing up on the dash. Engine went into 'get you home mode', so wouldn't rev, this is perfectly normal, so don't assume the worst and that the car is on it's way out, as I did!
Firstly changed the lower turbo pipe with a silicon replacement item. Didn't cure the problem. However the old original one was starting to go, so worth doing anyway, get the redesigned silicon item and you shouldn't have to do the change it again. It's the same price as the original, so don't bother replacing with an original hose, which will just go again anyway.
New genuine Pierburg EGR off ebay was around £130, used the guide from this site to change it (guide was brilliant btw) and 40 minutes later, new one in place. One thing I'd add to the guide is to clean out the port on the manifold that the EGR connects to
. There was a load of soot in there and five minutes or cleaning, gently, with an old tooth brush and blowing down the port and all the crud came out. Also double check when you've reconnected the electrical plug on the EGR, that it is firmly in place too.
Just come back from a 'spirited' test drive and the car is transformed. Think the car, whilst working well when I got it, has really benefitted from the change. Incredible mid-range from what is a smallish engine, lovely! (It's not been remapped).
So, you really can do the job yourself. It's one of the easiest repairs I've ever done on a car, honestly. So even if you are a complete beginner at doing jobs on cars, take your time and give it a go, you'll be chuffed that you did and saved yourself a few quid in the process. One final thing, do what I did, take plenty of photo's of the dismantling, with your mobile phone, it helps if you forget what to put back where.