My 2.0T Quattro (manual) is running a little sluggish and suffers an intermittent miss at idle. Diverter valve has already been swapped out for latest D version. Have also changed the clutch switch which made a slight difference, however there is still a miss when the car sits at idle. The performance is also lacking compared to what it used to be. However, intermittently there is something that triggers in the car or a module that kicks back into life and transforms the drivability. This generally occurs when the car is sitting idle for a bit (in traffic or at lights) or switching engine off and on after its been driven for a bit. (This is what makes me think its a module that kicks back into life). It appears to be a airflow problem of some sort but we just cannot pin point it. The car has recently had a service during which the air filter was also replaced (clutch switch changed at same time). Any recommendations on where to go next will be much appreciated. Or a recommendation to decent specialist in east London will be good. Thanks in advance.