What does it mean?
This diagnostic code (DTC) is a generic powertrain code, meaning it applies to vehicles equipped with OBD-II. Although generic, specific repair steps may vary by make/model.
It indicates a fuel vapor leak or lack of purge flow in the EVAP control system. This means a significant leak has been detected.
The Evaporative Emission Control (EVAP) system prevents fuel vapors from escaping from a vehicle’s fuel system. Fuel vapors are routed through hoses to a charcoal canister for storage. Later, when the engine is running, a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
Evaporative emission related fault codes include P0450, P0451, P0452, P0453, P0454, P0456, P0457, P0458, and P0459.
Symptoms
You will likely notice no driving issues.
Causes
A P0455 code most likely means one or more of the following has occurred:
A loose or improperly installed gas cap
A non-compliant gas cap (i.e., not a factory/original brand)
Other leak or damaged part in the EVAP system
Possible Solutions
With a P0455, the most common repair is to:
Remove and reinstall the gas cap, clear the codes, and drive for a day to see if the codes return.
If not, replace the gas cap and/or
Inspect the EVAP system for cuts/holes in the tubes/hoses (you may hear a vacuum noise or smell fuel), repair as necessary
Other EVAP DTCs: P0440 – P0441 – P0442 – P0443 – P0444 – P0445 – P0446 – P0447 – P0448 – P0449 – P0452 – P0453 – P0456