Hello guys,

I bought a brand new air intake hose for my 1991 4runner 3vze 5 speed. Well, I noticed I got a very strange extra hose coming out of the air intake hose and going all the way to the other side under the intake manifold. What is this sort of upgrade? Where it possibly connects and what purpose can it serve at all? Should I just shut it and run without it? Very strange thing...

Here are the pics:


Mystery hose highlighted in red.

Connection to the air intake hose.

Going under the manifold on the passenger side.

 

Holy, moly! That's a lot of after-market plumbing! Does this truck run on LPG (Liquified Petroleum Gas) or something?

In the usual configuration, the port on the side of the intake hose connects to the top of the left valve cover, to remove crankcase gas. On the right side, there is a PCV valve in the valve cover, which has a vacuum line to a port in the plenum (upper intake manifold) right above it. Your long hose that goes from the port on the intake hose LOOKS like it goes to where the PCV valve would be found. Which suggests that the PCV vacuum port (not shown in your photos) is used by something else, and whoever stitched all of this together was looking for another place to run the PCV valve.