I have a 2002 Supercharged Xterra. Had a "friend's" shop do a head gasket (HUGE mistake!). I won't bore you with the long horror story. However, as I've inspected the engine compartment, I've notice multiple vacuum lines disconnected.
Does anyone have a good diagram or good engine compartment photos to show all the connections?? The ones I've found online so far show some connections, but not where all terminate. Many thanks!!
If there is a vacuum port that is open on the intake manifold and you plan to use the vehicle you should cap it off until you figure out where it should be connected. If you leave it open you will run lean because your feeding the engine u-metered air so the computer can't adjust for it. This could be causing your rough idle. I'm not too familiar with the SC, but the missing line could be from the fuel pressure regulator, which is on the fuel rail back in behind and below the intake manifold on the regular 3.3l. I suspect it's the same location on the SC.