Evaporative Canister
WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.
Evaporative (EVAP) canister is used for evaporative fuel control on all vehicles. The evaporative emission control system stores gasoline fumes from fuel tank in a carbon canister until fumes can be drawn from carbon canister into the intake plenum.