– Incorrect fuel filler cap used
– Fuel filler cap remains open or fails to close
– Foreign matter caught in fuel filler cap
– Possible a noticeable fuel odor caused by the release of fuel vapors
The evaporative emission (EVAP) control system stores fuel vapor from the fuel tank in the EVAP canister temporarily to prevent it from escaping to the atmosphere and to enable it to be drawn into the engine by intake manifold vacuum and burned. In addition, the onboard refueling vapor recovery system (ORVR) stores fuel vapor generated when refueling in the EVAP canister.
The EVAP control system leak detection method improves the accuracy and frequency of the detection by determining faulty components and vapor leakage for each part. The EVAP control system (from the purge valve to the fuel tank) is divided into two parts. One is the “EVAP Canister Side” (from the EVAP two way valve to the purge valve) and the other is the “Tank Side” (from the EVAP two way valve to the fuel tank). There is 0.04 inch leak detection and 0.02 inch leak detection. If the 0.04 inch leak detection results are OK, the 0.02 inch leak detection runs.