I changed the valve cover gasket on my 98 2.2 and as you know everything on top has to come off to get to it.
Put it all back together and I have a connection for a vacuum line in which I can't find the hose for it. I probably tucked it away so I could find it again. Truck seems to run fine. Well that didn't work. If I knew what it was for, maybe I can trace it back.
Hope someone can help. Heres a picture.
http://invite.homestead.com/Picture1.jpg