P0446 Evap System Vent Blocked

Anyone correct this problem code by anything other then a new gas cap?

ALSO, is the EVAP VENT something that would effect fuel economy?

no really, it is an emmisions system.

Check the EVAP canistor and make sure it doesn't have any water in it.

is the canister definately underneath the spare? i.e. - I need to remove the spare to get to it? I noticed some wierd box behind the drivers side rear wheel. Thought that was it. No?
Also, how do I make sure theres no water in it?

I honestly don't know where it is.

Does your repair manual state where it is?

not really