Honda Check Engine Code
P0455 on Honda
Evaporative Emission Control System Leak Detected (Large Leak)
Also covers: Acura
P0455 on Honda: what makes it different
P0455 shows up across nearly every Honda with an EVAP system because the large-leak threshold is easily tripped by something as simple as a loose gas cap, making it one of the most common check-engine triggers on Accords, CR-Vs, and Civics.
Most-affected engines
- K24 2.4L (Accord, CR-V)
- L15B7 1.5L Turbo (Civic, CR-V)
- J35 3.5L V6 (Odyssey, Pilot)
Common model years: 2008–2020
Most likely cause on Honda
Loose, damaged, or missing fuel filler cap
Known Honda engine-family issues
Honda's factory gas caps are known to lose their seal integrity after several years of use, which is the single most frequent cause of P0455 across Honda's lineup. In colder or salt-belt regions, filler neck corrosion can also contribute.
Honda-specific causes (most common first)
- Gas cap not tightened fully or missing after refueling
- Worn gas cap seal no longer sealing properly
- EVAP canister vent valve stuck open
- Fuel filler neck damage or corrosion allowing air leakage
- Purge valve stuck open creating a large-leak-like vacuum signature
- Cracked charcoal canister housing
Honda-specific diagnostic tip
Before running any tests, tighten the gas cap until it clicks several times and clear the code, then drive a short cycle; if it returns quickly, move to a smoke test since a large leak is usually easy to pinpoint visually.
Symptoms drivers report
- Check engine light
- Fuel smell around the car (occasional)
Typical repair cost on Honda
Most Honda owners fix P0455 for between $0 and $200, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Loose, damaged, or missing fuel filler cap — before throwing parts at it.
Honda P0455 FAQ
Will retightening the gas cap clear P0455 immediately?
The light won't turn off right away even if the leak is fixed — the EVAP monitor needs a full drive cycle to re-test and confirm no leak before the code clears.
Can a bad gas cap really trigger a check engine light?
Yes, Honda's EVAP monitor is sensitive enough that even a slightly loose or worn cap seal is a very common and genuine cause of P0455.
Related codes
Drive a different make? See the general P0455 guide for cross-vehicle causes and symptoms.
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Most common fix for P0455:
Replacement gas capAs an Amazon Associate, AXLY earns from qualifying purchases. General P0455 guide →
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