Evaporative Emissions System: Description and Operation

This system limits emission of fuel vapors into the atmosphere and prevents raw fuel from escaping the fuel tank. An expansion chamber for the fuel tank and vent lines are part of the fuel tank vent system. These components prevent raw fuel from escaping at extremely high outside temperatures and when the vehicle is driven or parked on an incline or non-level position. Vapors from the fuel tank are trapped in a container filled with activated charcoal. This canister is connected to the fuel tank vent system and allows fuel vapors to pass through it and deposit hydrocarbons on its surface. When the engine is running, fresh air entering the charcoal filter through an opening cleans the charcoal and routes these hydrocarbons, via the air cleaner, back to the engine where they are burned during combustion.