I have a 2000 MS LS 3L ok on the black air intake hose from the air box to the throttle body. after the Map sensor close to the throttle body there is a male tube fitting coming out and on the passanger side valve cover there is another male tube fitting. I guess there should be a vacuum tube hook up between these?? its never had one since I've owned it but wondering why someone would have removed it. or if I'm wrong totally on what the tube fittings are for??? Please anyone

It has not caused a CES light in over 12,000 but wondering thanks

 

I think it helps Positive Crankcase Ventilation (PCV) but I'm not sure... Either way I would cover it up cuz ur gonna get debris in ur engine...

 

Have you tried referencing a FSM?
Even a Chilton manuel will have what you need, if you don't use a web-based FSM.