Identify this
 

Can anyone tell me what this box is?http://forums.pelicanparts.com/uploa...1693869690.jpg

This is the charcoal canister. It includes the leak detection pump.

Underneath the canister is one hose that goes to the top of the fuel tank and another that runs back to the engine to the purge valve.

It also fulfills another purpose, to vent the fuel tank during refueling. If you cannot refuel because the pump shuts off a lot, replace this canister.