A fuel cap is a sealing cover on the fuel filler tube (which leads to the fuel tank) that allows the vehicle's tank to be refilled while keeping the fuel from evaporating out into the atmosphere at all other times. Many of them have internal vacuum relief valves that allows air in but not out, so the space that fills the tank as fuel is consumed can be filled with air, as opposed to becoming a vacuum that makes the fuel pump have to work harder.
Faulty Fuel Caps Video by Cars Simplified
- P0440 Evaporative Emission Control System Malfunction
- P0441 Evaporative Emission Control System Incorrect Purge Flow
- P0442 Evaporative Emission Control System Leak Detected (small leak)
- P0443 Evaporative Emission Control System Purge Control Valve Circuit Malfunction
- P0444 Evaporative Emission Control System Purge Control Valve Circuit Open
- P0445 Evaporative Emission Control System Purge Control Valve Circuit Shorted
- P0446 Evaporative Emission Control System Vent Control Circuit Malfunction
- P0447 Evaporative Emission Control System Vent Control Circuit Open
- P0448 Evaporative Emission Control System Vent Control Circuit Shorted
- P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
- P0450 Evaporative Emission Control System Pressure Sensor Malfunction
- P0451 Evaporative Emission Control System Pressure Sensor Range/Performance
- P0452 Evaporative Emission Control System Pressure Sensor Low Input
- P0453 Evaporative Emission Control System Pressure Sensor High Input
- P0454 Evaporative Emission Control System Pressure Sensor Intermittent
- P0455 Evaporative Emission Control System Leak Detected (gross leak)