Over time the factory turbo's variable geometry exhaust housing actuator system can rust through and/or stick. When the turbo's actuator rusts through or sticks the turbo's variable geometry is stuck and cannot adjust pitch according to boost pressure, resulting in poor performance. VW or Garrett will not sell these actuators by themselves, you must buy the whole turbo with exhaust manifold.
PDR solves this problem with our own PDR turbo actuator for the 1999-2003 VW TDi VNT15 and VNT17 turbo's. Our stock replacement actuators are made to factory specifications for PDR, simple to install and bolt in place of the existing factory turbo actuato