Hello Mike. My 2.2d was doing the same thing. Turned out to be EGR valve. Bought a £3 blanking plate on ebay, took 5 mins to fit. Problem gone, turbo kicks in quicker, she pulls even more and no soot! The engine management light will come on but it is just a code to say that the car is not getting enough Exhaust Gas Re-circulation, nothing bad. Going to get mine remapped and have the EGR deleted from the ECU so the light goes off =). All i can say is give it a go. Better than paying £200 for a new EGR valve. John.