P0455 on a Toyota: Causes, Fixes & Repair Cost

🟢 Low severity · drivable

Safe to drive — this is an emissions leak, not an engine problem, but fix it before your next emissions test.

What P0455 means on a Toyota

On a Toyota, P0455 means the engine computer has detected a large leak in the evaporative emission (EVAP) system, so fuel vapors are escaping. On Toyotas, a loose or missing gas cap is the most common reason, though a cracked EVAP hose or a faulty vent valve can also cause it.

Is P0455 common on Toyotas?

P0455 is a common code on Toyotas like the Camry, Corolla, RAV4, and Highlander, and it's usually nothing serious. Most of the time the fix is as simple as tightening or replacing the gas cap, so it's worth checking that before anything else.

Commonly reported on: Camry, Corolla, RAV4, Highlander.

Symptoms

Check engine light is on
Possible fuel smell near the car
No change in how the car drives
Code returns after clearing if the leak isn't fixed

Common causes

most common: Loose, missing, or damaged gas cap
common: Disconnected or cracked EVAP hose
common: Faulty EVAP purge or vent valve
less common: Crack in the charcoal canister

How to fix it

Fix	DIY?	Typical cost
Tighten or replace the gas cap	Yes	$10–30
Inspect and reconnect or replace cracked EVAP hoses	Yes	$10–60
Have a smoke test performed to find the exact leak	Mechanic	$50–150
Replace a faulty purge or vent valve	Yes	$30–120