Assume you mean the purge valve.

See Post #2 here:

http://www.traverseforum.com/33-engine-drivetrain/10233-2015-p0496.html

 

I remember a member was having issues. P0449 or P0496....
he changed the Purge valve in the engine bay.
But problem persisted,
the then had to replae the EVAP solenoid.
THis one- sits on top of the fuel tank.... so the tank does have to be dropped to replace.

 

rbarrios - Did you intend to have a link tied to the word "This?" If so, you didn't tie it.

 

yup... but messed it up..
I put i the post below instead. more informative.

 

I believe the part that is needed is # 3

it connects to the carbon canister (#1)

This part is located under the vehicle/by the tank.

this is an image from online (Dorman replacement)

the canister on the Lambdas.

I also found this on the Acadia forum- that backs up what I'm thinking.

"The P0449 is the EVAPORATIVE EMISSION VENT SOLENOID VALVE CONTROL CIRCUIT.
It is located in the evap emission canister which is on the top side of the gas tank, so
the gas tank has to be removed and then the canister and then the vent solenoid valve could be removed and replaced."



You can see its location at 3:03 sitting on top of the tank.