P0446 on a Toyota: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

You can keep driving, but fix the vent valve soon — many owners also notice the gas tank becomes hard to fill.

What P0446 means on a Toyota

On a Toyota, P0446 means the vent valve that lets air into the EVAP canister is not working right — it is usually stuck closed or clogged. When the vent can't open, pressure builds in the fuel tank, which is why many Toyotas with this code are hard to fill at the pump. The engine itself runs normally.

Is P0446 common on Toyotas?

P0446 is a well-known code on Toyotas like the Camry, Corolla, and RAV4. The vent valve lives inside or near the charcoal canister, and over time it gets clogged or sticks, especially on older models. A clogged vent line or a faulty vent valve wiring connector are the other common causes.

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

Symptoms

Check engine light on
Gas pump nozzle clicks off early or tank is hard to fill
Fuel smell near the fuel filler area
Normal driving otherwise

Common causes

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

How to fix it

Fix	DIY?	Typical cost
Clean or replace the vent valve	Yes	$60–180
Clear a clogged vent line	Yes	$20–60
Have a shop test the vent circuit and replace the valve	Mechanic	$150–350
Replace the charcoal canister assembly	Mechanic	$300–600