P0446 Code: Evaporative Emission Control System Vent Control Circuit Malfunction

🟢 Low severity · drivable

Safe to drive — this is an EVAP vent-valve fault, not an engine problem. Fix it before your next emissions test.

What P0446 means

The vent valve that controls airflow into the EVAP canister isn't working correctly — it may be stuck, clogged, or have a wiring fault. This valve normally opens to let fresh air into the canister during a purge cycle.

Symptoms

Check engine light is on
Possible difficulty filling the fuel tank
Usually no driving symptoms

Common causes

most common: Faulty or clogged EVAP vent valve
common: Wiring or connector problem at the vent valve
less common: Blocked or clogged canister vent filter

How to fix it

Fix	DIY?	Typical cost
Replace the EVAP vent valve	Yes	$30–150
Inspect and repair the vent valve wiring and connector	Yes	$10–50
Clean or replace a clogged canister vent filter	Yes	$10–40

Frequently asked questions

Can I drive with a P0446 code?

Yes. It's an emissions vent-valve fault that won't affect drivability. Fix it before your next emissions test.

What is the most common cause of P0446?

A faulty or clogged EVAP vent valve. It's often a straightforward, inexpensive replacement.

How much does it cost to fix a P0446?

Usually $30–$150 for a new vent valve, plus a small amount if wiring is involved.

Related codes

P0440 Code: Evaporative Emission Control System Malfunction

P0455 Code: Evaporative Emission Control System Leak Detected (Large Leak)

P0449 Code: Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction

P0446 by vehicle brand

Causes and repair costs for P0446 differ between makes. Pick your brand for the specifics.

P0446 on a Toyota

P0446 on a Honda

P0446 on a Ford

P0446 on a Chevy

P0446 on a Nissan

P0446 on a Mercedes-Benz

P0446 on a Volkswagen

P0446 on a Hyundai

P0446 on a Subaru

P0446 on a Mazda

P0446 on a Jeep

P0446 on a Lexus

P0446 on a Volvo

Related guide: How to Reset a Check Engine Light →

Updated 2026-08. This page is informational and not a substitute for professional diagnosis.