This part acts as a PCV valve, as it provides a one way exit for gasses built up in the crankcase. Over time, contamination might cause reduced air flow and cracks can occur in the housing. If your car is experiencing a loss of boost pressure, a decrease in performance, as well as rough idle, this valve might to be blame. This valve sits in the in the intake hose that goes down to the turbo inlet.

Application Notes: Fits select years, A4 2000-2003, Passat 2003-2005, GTI/Jetta 2000-2002