I have found a broken vacuum line and have failed to figure out where it is supposed to go. It is the bottom line connected to the cold air intake tube on the passenger side just before the throttle body. Part # 07L 103217B . It is routed around the back of the engine and has broken off in the area of the oil filter housing. I have just finished adding intake spaces and cleaning the valves along with various gasket replacement. I have no recollection of this hose though.
Pictures will always help but if you removed your intake manifold you should have good access to the lines. That line is part of the PCV system. Your going to want to make sure that is working or your going to have some issues with the fuel trims and the car running well.