EVAP Canister
WARNING: This page is about a different car, the 2014 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
EVAP canister stores the generated fuel vapors in the sealed fuel tank to activated charcoals of EVAP canister when the engine is not operating or when refueling to the fuel tank.
Courtesy of NISSAN NORTH AMERICA, INC.