Fuel Injected Engine: Non-Turbo

When engine is not running, vapor from expanding fuel in fuel tank collects in expansion tank. Vapor flows from expansion tank and into charcoal canister through vapor separator and 2-way valve. Intake manifold vacuum controls the purge control valve on the canister. When the purge control valve is opened, vapor flows from the canister into the throttle body.

Fig 1: Fuel Evaporation System (Fuel Injected Engine - Non-Turbo)

Courtesy of SUBARU OF AMERICA, INC.