Code Definition: P0455 - Evaporative Emission Control System Leak Detected (Large Leak)
The P0455 code is a specific trouble code that indicates a large leak has been detected in the evaporative emission control system. This system is responsible for capturing and storing fuel vapors from the fuel tank and preventing them from escaping into the atmosphere. When a large leak is detected, the code is stored in the engine computer and the check engine light is illuminated.
Possible Causes:
- Faulty or damaged fuel tank ventilation hose
- Cracked or broken fuel tank filler neck
- Loose or damaged fuel cap
- Hole or tear in the fuel tank
- Damaged or clogged charcoal canister
- Malfunctioning purge valve
- Worn or damaged seals or gaskets in the evaporative emission control system
Symptoms:
- Check engine light illuminated
- Fuel odor from the vehicle
- Increased emissions
- Difficulty starting the engine
- Poor engine performance
- Reduced fuel efficiency
Diagnostic Procedure:
- Scan the vehicle for any other codes that may be present. If there are no other codes, proceed to step 2.
- Inspect the fuel tank and surrounding components for any signs of damage or leaks. Look for cracks, holes, or tears in the fuel tank, fuel filler neck, and fuel tank ventilation hose.
- Check the fuel cap for proper installation and tightness. Make sure the cap is securely fastened and not loose.
- Test the purge valve for proper operation. Use a scan tool to command the purge valve open and listen for air flow through the valve. If there is no air flow, the valve may be clogged or faulty.
- Remove the charcoal canister and inspect it for damage or clogging. Check for any holes, cracks, or obstructions in the canister and replace it if necessary.
- Check the seals and gaskets in the evaporative emission control system for any signs of wear or damage. Replace any damaged seals or gaskets as needed.
- If none of the above steps resolve the issue, suspect a faulty or damaged fuel tank and consider replacing it.
Repair Information:
- Replace the faulty or damaged fuel tank ventilation hose with a new one. Be sure to use the correct replacement part number for your specific vehicle make and model.
- Replace the cracked or broken fuel tank filler neck with a new one.
- Install a new fuel cap if the existing one is damaged or loose.
- Repair or replace the fuel tank if it is damaged or leaking.
- Replace the charcoal canister if it is damaged or clogged.
- Replace any damaged or worn seals or gaskets in the evaporative emission control system.
- If the issue persists, consider replacing the entire evaporative emission control system or consulting a professional mechanic for further diagnosis and repair.
