Just noticed the vaccuum port (marked with red ) is missing a vaccuum line (The brass port shows markingsthat indicate a line had been there 'recently'). The Vaccuum port in front of it connects to the first position on the airbox in the second photo. I cannot find an unattached line or another open port. (The port does create suction when the engine is idling.)

Help!

Where should it connect? Can't seem to find a diagram..

Thanks for your help!
1999 S80 2.9 L Non-Turbo , original owner, 92K Miles