Emissions Vapor Canister (Evap. System)

[PHOENIX]

Sometimes while driving the truck I smell some gas.
The real problem is after the truck has been turned off for awhile.
It really starts smelling like gas, big time.
If I park the truck in the garage the smell (fumes) are so strong you
can smell them in the house. Enough to clear out the house.
When I park in the driveway you can smell it in the house if the front
door is open. Its so strong smelling I wouldn't light a match anywhere
near it. A few times I thought twice about turning the lights on in the
garage.

I tracked it down to the vapor canister. No doubt the smell is coming
from the canister. All the lines are hooked up correctly. I am going to
follow some tests in the shop manual.

Has anyone ever had this problem?
Can I change out the charcoal inside the canister (filter?)?
Is it a dealer part?
Just looking for info from those who have worked on the canister.

Thanks,