P0446 on a Honda: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Safe to drive, but fix the vent system soon — you may notice fuel smells or trouble filling the tank.

What P0446 means on a Honda

On a Honda, P0446 means the vent valve that controls airflow into the EVAP canister is not working as it should. The valve can stick closed or the wiring to it can fail, so the computer sees an incorrect vent circuit. The engine runs fine, and the check engine light is usually the main sign.

Is P0446 common on Hondas?

P0446 shows up on Hondas like the Civic, Accord, and CR-V as the canister vent valve or its wiring ages. The vent valve is mounted near the charcoal canister, and it can get stuck from dirt or fail electrically. On some models a clogged vent line behind the filler area is the cause.

Commonly reported on: Civic, Accord, CR-V, Pilot.

Symptoms

Check engine light on
Faint fuel smell near the rear of the car
Possible slow or hard fuel filling
Normal driving and power

Common causes

most common: Vent valve stuck closed or failing
common: Faulty vent valve wiring or connector
common: Clogged vent line or canister filter
less common: Damaged charcoal canister

How to fix it

Fix	DIY?	Typical cost
Replace the vent valve	Yes	$60–170
Repair vent valve wiring or connector	Yes	$30–90
Have a shop test the vent circuit and replace the valve	Mechanic	$140–330
Replace the charcoal canister assembly	Mechanic	$280–550