Where can I locate the evap vent valve on a 99 Yukon?

[Rael]

I'm getting a p0449 code and read that you can try blowing out the evap vent with compressed air. The Haynes manual isn't much help and I can't seem to locate it. Anyone know where I can find it?
Thanks

 

[metaljunkie]

I think it is on the charcoal canister on the drivers side next to the spare battery tray.