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
P0440 Code: Evaporative Emission Control System Malfunction
P0455P0455 Code: Evaporative Emission Control System Leak Detected (Large Leak)
P0449P0449 Code: Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.