hello I have the following problem: have converted my audio a8 3.7 to 4.2. But now one of the four vacuum connections at the angle end at the suction bridge (if one is standing in front of the car at the back side) remained free. are connected brake power amplifiers, hose to the engine ventilation and gasoline pressure regulator. the suction tube switching unfortunately does not work, maybe it could have something to do with it. would not be if someone could tell me what belongs to this free nipple for a tube.
Thank you
mfg
Edited by thilo