The only one I didn't label......


https://drive.google.com/file/d/0B3Z...w?usp=drivesdk

 

Is that a wire or a vacuum line ?
It looks like the one that operates the dash controls.

 

Yes. It's kinda stiff. More like a hose than wire. Where might it go?

 

Yes it's more like a vacuum line. Stiff. Any idea where it hooks up?

 

The boot will mate up to the male end of that near by.
Look for another vacuum line that looks similar in size _ probably hanging over the valve cover somewhere around the exhaust manifold.

Yours is a 2002 and 3 years newer then mine, so things are a little difference.

 

Looks like a Grey vacuum hose that comes out of the firewall.
It would go to the Heater hose valve, seen behind your hand in picture, it closes valve when No Heat or Max AC is selected.

 

It reminds me of the vacuum line that goes to the Fuel Pressure Regulator, though the line to mine is much smaller. Not even sure you have a regulator, but mine is attached to the front of the passenger fuel rail. Just a guess.

 

I discovered this vacuum hose off, and for the life of me cannot find a place to plug it.. Swear I've gone over every inch of engine where this thing reaches.

Seems to be a consensus that it's the heater control, however my heat and AC work fine, and not just out of the defrost vents as suggested.

Truck is running EXTREMELY rough and have been getting misfire CEL's.

Pictures here show the same as the OP. It's definitely a vacuum, it suctions to your finger.

Thanks,

Matt

Mystery Vacuum Hose 1
Mystery Vaccuum Hose 2