Impreza Outback Sport AWD F4-2.5L SOHC (2002)
While Refueling
As the fuel enters the fuel lank, the tank inside pressure increases. When the inside pressure becomes higher than the atmospheric pressure, the
port of the vent valve opens, allowing the fuel vapors to be introduced into the canister through the vent line. The fuel vapors are absorbed by
charcoal in the canister, so the air discharged from the drain valve contains no fuel. When a filler gun is inserted, the shut-off valve closes the
evaporation line.