On my pickup there is a plug that sits on top of the valve cover just forward of the PCV valve. The female end, which is mounted to the valve cover, is black, and the male end is grey. Right now the plug is sitting not connected on top of the valve cover-I noticed it when I went to check my PCV yesterday. What is this?

 

does it have vacuum hoses on it? could be a VSV (vacuum switching valve)

 

Without going out to look at it again I'm not 100% sure but I think so-what does the VSV do? I have an oil consumption problem that could be caused by a vacuum issue-could that be part of it? I'm going to replace the PCV this weekend to see if that helps.

 

Did you ever get this figured out? I have the same issue. The gray plug is not attached and it doesn't really fit anywhere.