P0442 on a Toyota: Causes, Fixes & Repair Cost

🟢 Low severity · drivable

Safe to drive — this is a small emissions-system leak, not an engine problem. Fix it before your next emissions test.

What P0442 means on a Toyota

On a Toyota, P0442 means the EVAP system, which captures fuel vapors from the tank, has a small leak. The engine runs fine, so the check engine light is usually the only symptom. It's an emissions issue, not a drivability issue.

Is P0442 common on Toyotas?

P0442 is one of the most common EVAP codes on Toyotas like the Camry, Corolla, RAV4, and Highlander, especially as the gas cap seal and EVAP hoses age. A loose or worn gas cap is the top cause, followed by small cracks in EVAP hoses and aging purge valves. Cold weather can make the code appear more often.

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

Symptoms

Check engine light is on
Possible faint fuel smell
Usually no driving symptoms

Common causes

most common: Loose, missing, or damaged gas cap
common: Small leak in an EVAP hose or fitting
common: Faulty EVAP purge or vent valve
less common: Small crack in the charcoal canister

How to fix it

Fix	DIY?	Typical cost
Tighten or replace the gas cap	Yes	$10–30
Inspect and replace cracked EVAP hoses	Yes	$15–80
Have a smoke test performed to find the exact leak	Mechanic	$50–150
Replace a faulty purge or vent valve	Yes	$40–160