Hi all, Newly registered to the forum with a few questions! I've been looking around here a while trying to diagnose my problem and tried a few things but now I need the help of more mechanically gifted people! I have an A4 Avant Quattro 1.9TDi, AFN engine. It seems really sluggish upto 50/60mph and when you hit 3000rpm at higher speeds (40mph+) the turbo seems to cut out and it has even less power and then idles rough. If i turn it off and on again the turbo "works" again. I've changed the vacuum hoses for silicon ones and tried unsticking the turbo vanes with oven cleaner but it still has the same sluggishness. I've had the codes read and it comes up with something like Injection Regulation Deviation? is this a timing issue? and do the problems above sound like a bad turbo or something else? Sorry for all the questions but I'm hoping to be able to save my Audi! Any help would be very much appreciated!