What is this vacuum line?

[PStansberry78]

I found this vacuum line like this when I went to add oil to my truck the other day. It seems obvious where it should hook in, so I did. That day, it started running rough. Surging during acceleration, sputtering out the tailpipe.

What is this line?

 

[PStansberry78]

It did that for a couple of days, but seems (relatively) fine today.

 

[Maniak]

That looks like one of the lines from the evap system. The box with the 2 round things on the top in the pic is the evap canister. One line goes from there to the tank and another line goes from there to a fitting under the throttle body. The one that goes to the throttle body also has a solenoid/valve between the evap canister and TB which opens when the vehicle is warm/running so it can pull fuel vapors from the charcoal canister (evap canister) and burn them off.

~Mark

 

[vq5speed]

Yeah it looks like it should plug right into that hose its laying on...

 

[BrooklynBay]

It unplugged from the fitting. You could verify it by checking the vacuum diagram under the hood.