General Information

The first Evaporative Emission (EVAP) systems were introduced in the 1970's as part of the overall scheme to reduce the amount of fuel vapors (hydrocarbons) escaping into the atmosphere. To accomplish this, the EVAP system continuously transfers the vapors in the fuel tank to a carbon storage container, known as the EVAP/carbon canister. The EVAP canister stores these vapors until the Engine Control Module (ECM) determines the engine is ready to burn the fuel vapor. It is then drawn/purged along with fresh air, into the air intake. The vapors then go through the normal combustion process.

The components of the evaporative emission system are as follows:
1. EVAP Vent Solenoid - located on the upper end of the fuel filler pipe, just behind the left rear wheelhouse liner.
2. Fuel Tank
3. EVAP Canister - nested on the top of the fuel tank at the left, rear corner.
4. Fuel Tank Pressure Sensor - inserted on the top of the right rear portion of the fuel tank.
5. Fuel System Hoses
6. EVAP Service Port - located in the canister purge line near the canister purge solenoid.
7. EVAP Purge Solenoid - mounted on the passenger side of the vehicle near the EGR solenoid.