Evaporative Emission System Leak Detected (Ford)
What does P1455 mean?
The P1455 code means the vehicle's onboard diagnostic system has detected: Evaporative Emission System Leak Detected (Ford). This is a low severity code.
Common Symptoms
- Check Engine Light illuminated
- Faint fuel smell near the vehicle
- Slight decrease in fuel economy
- Fuel cap may feel loose or not click when tightened
- Occasional rough idle after refueling
Probable Causes (Ranked by Likelihood)
- Loose or damaged fuel cap Very High
- Cracked or deteriorated EVAP hose High
- Faulty purge valve Moderate
- Leaking fuel tank filler neck Moderate
- Damaged charcoal canister Low
Step-by-Step Diagnostic Procedure
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Inspect the fuel cap for cracks, worn seal, or improper seating. Tighten and clear the code to see if it returns.
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Use a smoke machine to pressurize the EVAP system and visually identify any leaks at hoses, connections, or the canister.
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Check all EVAP hoses from the fuel tank to the charcoal canister and purge valve for cracks or loose clamps.
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Test the purge valve with a scan tool by commanding it open and closed while monitoring fuel tank pressure changes.
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Inspect the fuel tank filler neck and its rubber seal for corrosion or cracking.
Frequently Asked Questions
Is P1455 the same as a generic EVAP leak code?
P1455 is a Ford manufacturer-specific code for EVAP leaks. It is similar in nature to generic codes like P0442 and P0455 but uses Ford-specific testing criteria and thresholds.
Can a bad gas cap really cause this code?
Yes. A loose, cracked, or worn gas cap is the most common cause of P1455. Always check the cap first and try tightening or replacing it before moving on to more expensive diagnostics.
Will P1455 cause my vehicle to fail an emissions test?
Yes. Any active Check Engine Light related to the evaporative emission system will cause a failure on OBD-II emissions inspections in most states.