Hi guys! I just purchased a used 2001 Volvo S60 non-tubro and noticed this wire was disconnected. It is coming from the engine itself. Any idea where it should go? Thanks!

It is the solid black line on the left in the posted picture.

 

That looks like a vac line to me. Try looking for a rubber hose that it plugs into on the air cleaner housing. I'll go check out my 03 if I can find the same tube and to where it's connected.