I've just picked up a '96 tdi(90) with 230k on her.Now at that kind of mileage im not expecting too much but the cars very down on power especailly after 2000rpm it feels like someones pulled on the handbrake. Its also smoking really badly even if revved while stationary, dark grey/ blacky stuff.Now would I be right in thinking the first thing to do would be change the MAF as this is faulty making the ECU overfuel and therefore be smokey? Are there any other things i should be changing/cleaning? EGR valve or inlet manifold??