I have an '06 Jetta w/ 1.9 TDI with about 112,000 miles. Recently I started leaving a huge black clould behind my car regardless of how fast I accellerated. Local repair shop replaced Mass Air Flow Sensor, which helped for about 50 miles, then same problem. They replaced M.A.F.S. a second time & same problem. After having it for about 10 days, they finally "think" it is the Vacuum Actuator on the turbo. There is an exhaust leak sound from under the engine and the car is running very sluggish, both of which they attribute to the Vacuum Actuator issue.
Does this sound legit? Does anyone have a VW repair shop they recommend in the the Clear Lake/Friendswood, TX area?