Vacuum canister lines

[myk]

Wish I had a pic, but maybe someone will understand me. Removed the Vacuum box and all other uneeded lines from everywhere to clean up the bay a little bit. I was just wondering what the line that comes out of the vacuum canister to the right and connects to a hard line on the firewall is, it looks like it goes down somewhere (the hardline). The vacuum diagram on the hood didnt help much . Its not PS or at least I dont think PS has 2 lines coming from that canister.

[4CYLPOWER92]

It goes to a two way valve, and back to the fuel tank.

[myk]

mmm thats what I thought, do I need this line? I mean thats the only line hooked up to that canister right now, seems kinda important , there is that pcv valve on top of the canister for 2 lines but I only have one more port on my intake manifold that is open. The line is just chilling connected to the canister, but there is no vacuum pressure in it, the car has been running fine for 2 days now.

Kinda worried, maybe change it to a two port thing on the cannister and just have the intake mani and other line hook up to it?