Air tube connector on air filter housing

Hey all.
I bought a new factory air filter housing for my 95 2.7 L 4x4.
it had a cone filter on it pulling air from the engine bay and nylon straps holding it in place.
I had to drill a hole for the it sensor.
on the engine side of the air box lid is a 3/8 inch nipple that I had to buy a plug for since it's after the air filter.
Any clue what it's for? I can't find any plugged air lines anywhere.
The box was bought from Rockauto so it may not be needed but want to make sure I'm not missing some thing.
Attached pic. It had a plug closing it up for now.

 

Most likely the same housing is used on the V6 motors. I'm thinking my V6 trucks have a hose that connects to this nipple after the end is cut off. I can't remember what it goes to.

 

Hmm
The service manual shows it in use on the 3rd engine.

 

My 99 had an evap line that came from the other side of the engine bay that connected to this.

 

I have the black canister on the drivers side fender, but no open or plugged holes.

 

That hose connects to here on your canister under the hood.

 

interesting. I don't have that charcoal canister. I have the round one.

 

Picture of my canister. Thought for a few that maybe I has the 2RZ but the hood sticker states I have the 3RZ.

 

Hmmm. Interesting. I guess in your case then, it is not needed?

 

That is what I am starting to think.

 

Thanks for the help!