97 4Runner SR5, 3.4L 2WD Auto. I was looking under the hood and noticed 2 male hose connections coming off the top of the throttle body facing rear. They have what appears to be factory installed, easily removable plugs blocking them. I looked around and couldn't find anything that I could connect to them or anything that could receive a hose connection. I checked the Haynes manual and it says it is the throttle body vacuum port, I assume has something to do with the throttle position sensor. Does these need to be connected?

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The 2 3.4L i have owned have the same thing. I'm not sure what they connect to, but you don't have it on your truck. I assume its for an option, or possibly emissions, in another country.

Makes it easy to check vacuum readings though.

 

There is no known use for these. The FSM, when instructing as to how to clean throttle body, says to blow out TB passages with compressed air, and clearly shows a nozzle applied to one of these dead end ports. I therefore believe they are simply clean-out ports, until someone posts a better story. In any case, no need to connect them.

 

Could be used for an ADD system that uses vacuum to actuate.
Which would explain why you don't have it on your 2WD.

 

unused vacuum lines. possibly EGR (for older emissions) and whatnot
and another one to simply hook up a vacuum gauge and get a reading

 

I have the vacuum ADD on my 4WD. That line goes to the manifold, not the TB. Sticking to my story.