OXYGEN SENSOR AND RELATED COMPONENTS. Right.4.0 LITER. VAPOR CANISTER. Exhaust Gas Recirculation (EGR) Vacuum Delay Valve. Location-Engine Bay. Vapor Canister Purge Solenoid. Regulator. Switching. Air Switch. Exhaust Gas Recirculation (EGR) Delay. Vapor Canister Purge Solenoid.