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 purge control valve on canister. When the purge control valve is opened, vapor flows from canister into the throttle body.

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

Courtesy of SUBARU OF AMERICA, INC.