Could it be a bad vapor canister. I see that this is plastic unit that sits on top of the gas tank. I know the Vapor Canister Vent Solenoid was plastic and some of the rubber tubing could stand to be replaced.

I would assume the tubing here could be a culprit, otherwise could it be a faulty vapor canister purge valve or related tubing which sits on the throttle body I believe. I just want to make sure the points which could be responsible for the code.