Evaporative Emission

Monitor fuel vapors from the fuel tank to ensure proper capture within the canister.

What is evaporative emission (EVAP emission)

Evaporative emissions are fuel vapors that escape into the atmosphere from a vehicle's fuel tank and other parts. Evaporative emission control systems (EVAP) are designed to prevent these vapors from escaping. This emission is typically applicable to SI engines.

Sources of evaporative emissions

Fuel tank leaks, Fuel lines leaks, Fuel permeation through the fuel tank walls, and Fuel relief through the valves on the carbon canister.

How the EVAP control system – Charcoal Canister works

Fuel vapors are created in the fuel tank as a result of evaporation. When the fuel tank pressure becomes too high, the vapors are transferred to the charcoal canister. When the engine is running, the vacuum in the intake manifold draws the vapors from the canister into the engine. The vapors are added to the incoming air/fuel mixture and burned in the engine.