Just a quick q for any of you who may have some understanding of my issue... I have a 2001 2.5TDI Q Avant with 173k on the clock that apart from a few minor issues runs very sweetly. However I have noticed that on occasion on hard acceleration between 3rd and 4th gear the engine dies and will not rev at all...I often have to drop back to third in order to "restore" the turbo spooling up and even miss 4th altogether in order to continue accelerating. This has caused more than one "close" call when overtaking and suddenly feeling like I;ve come to a dead stop when alongside the vehicle I;m trying to overtake!! I assume it's my MAF...have tried to put a new one on but after buying one off ebay which purported to be a direct replacement and put my car in limp mode, I am reluctant to do this until I;ve eliminated any other issues.... advice please??