Any idea what this hose is?

Was looking around the internets and couldn’t figure out what this hose was. Anyone know? TIA!

 

I believe it goes to the charcoal canister for the EVAP system.
I sends fuel vapor from the tank into the intake to be burned….IIRC

 

That is exactly what it is.

 

Actually that hose is the fresh air line that goes to the charcoal canister. When the purge valve is being cycled, fresh air (that is filtered by the engine air filter)is drawn from the air box through the canister to clear the fuel vapor off of the charcoal and then is drawn into the intake through the purge hose and purge vsv (vacuum switching valve). Conversely, when you are filling your truck up at the gas station the air pressure that is building in the tank as the fuel rushes in must be vented so it is sent to the charcoal canister where the canister collects the vapor and the now fuel vapor free air is routed to the air box through that same hose. If you were to clamp it off, the effect would be that when you filled up,the fuel would spit back up the filler neck and kick the pump off. But TN is right that it is part of the EVAP system.

 

Think that is just a fresh air supply....

dont think you want to vent gas fumes into the filter media, or dumped right on the MAF sensor....

there's a pressure valve built in the other end of the canister.....
thats different from the external purge one....

So the pressure valve and the breather vent just dump into the air....

only the purge sends stuff into the intake .....



here's a pre 2003 one...

 

this blue one should be your purge....

 

You could even eliminate that fresh air line with one of these....




I'm chasing an evap code....so I'm uncomfortably familiar with all this....