Ok.. Had my TDi a few years now.. its just passed its MOT at 177k (97') I have a problem with the power in the engine.. When I am accelarating the power doesnt seam constant as if something it holding it back or not pulling enough air. I have change the MAF and N75 Solonoid. And no resolve. I have taken it to Audi and they said change the MAF I did.. No change, I did a bit of readon on here and changed the N75.. This is kinda getting fustrating as I took my Stainless Magnex exhaust off and put origional one back on and no change.. Anything else I can check as all the pipes are clean and clear.. IT is some sort of eletrical as when the engin off and back on it has power but then drops off again.. usually around the 60MPH mark.. Hitting 80MPH it gets to 75/78 then it just powers down as if something has closed.. Im bored of audi saying "it could be this that and the other" I need a final answer as them getting me to buy parts I don't need is really killing my wallet. Any thoughts??