P0455 on a Honda Accord
P0455 means evaporative Emission System Leak Detected (Large Leak). On the Accord, a few causes come up far more than others.
What P0455 usually means on a Accord
P0455 flags a large evaporative-system leak on the Accord, most often from the gas cap or the canister vent valve. Fuel vapor is escaping instead of being routed to the engine to burn. It will not hurt driveability but will fail an emissions test. Honda's vent valves and aging EVAP hoses round out the usual causes.
Most common causes on the Accord
- Loose or worn gas cap
The most common P0455 cause on Accords; check and re-seat the cap first.
- Canister vent valve stuck open
Honda vent valves stick, especially in salt-belt cars, preventing the system from sealing.
- Cracked EVAP hose
Aged lines near the tank and canister split and leak large vapor volumes.
- Damaged EVAP canister
A cracked charcoal canister leaks and sets large-leak faults.
What P0455 costs to fix on a Accord
A gas cap is a fifteen-to-thirty-dollar fix that clears many of these after a few drive cycles. The canister vent valve is a moderate, accessible part on most Accords. Only a full canister replacement approaches the higher end, and it is still a minor repair overall.
Year, engine and mileage change the answer. Start a case and Redline weighs these causes against what your car shows, then names the check that would settle it.
Other codes on the Honda Accord
Related symptoms
Honda Accord problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0455 behavior is covered on the main P0455 page. Confirm with a scan tool before buying parts.
P0455 on your Accord?
Every problem becomes a Case. Tell Redline what your Accord is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.