Just bought a 2000 A6 4.2. From the front of the engine a few vacuum hoses come out. One was open and dangling on the driver side at the front end of the engine. I plugged it. Where do you think it should connect to?
The others from the same "trunk" go to seconary air injection, intake manifold flap actuators and vacuum reservoir.

 

Attach a picture and someone might be able to help.

 

here's a picture http://web.me.com/tacksya