I am having under and overboost issues with my 2005 TDI Passat. At high boost, the car goes into limp mode and has to be reset. This just began on a recent trip to go climbing with some friends. I took it to the dealer because I was 300 miles from home. They couldnt tell what was going on other than the codes. He said it could be a bad sensor or turbo and he wouldnt know without throwing parts at it. I replaced the N75 and the boost sensor hoping for an easy fix. It seems to be better but still goes into limp mode if I get on it hard. Below is a video of a mityvac hooked up to the VNT. It seems to move to about 15 on the gauge and then stop. At the end it sometimes "pops" a little and isnt smooth. Next step is taking apart the exhaust and cleaning the turbo with oven cleaner. Should I also remove and test the actuator off the car?