This may be of some help those who have a hesitation at around 2k rpm or when backed off or very light on the throttle. I have had this problem for a few months now and have finally found the cause after much changing of parts ie ptu, tps , lamba probes, water temp, injector connectors and spark plugs all of which made no differance to the hesitation. What i have found is that the dam hard to get at EGR valve is to blame ( my only problem now is how to completly disable the dam thing while the engine is still in the car) I have temporaly removed the vac line to it and blocked the soliniod outlet, then taken a syringe and pressurised the valve to complety close it then trapping in the pressure. Having done this the hesitation is complety gone only wish i tried it first before buying new parts. Only one problem if the pressure leaks my hesition is back, i have tried to get at the flanges near the throttle bodies but cant undo the bolts while the engine is in the car, i am thinking of drilling the pipes and filling with metal glue any idea any one ?