OBD codes / P0446
P0446
MinorEVAP Vent Control Circuit Malfunction
P0446 is low-urgency — it won't change how the car runs or affect safety. The one annoyance is that a stuck-closed vent can make the fuel pump click off early while refueling. Fix it at your convenience; it will fail an emissions test until then.
What this code means
The EVAP vent valve lets the charcoal canister breathe and seals it off during self-tests. P0446 is an electrical or mechanical fault in that vent control circuit — the computer can't operate the valve correctly. The usual cause is a failed vent valve (often clogged with dirt or spider webs, since it sits low near the canister), a blocked vent line, or a wiring/connector problem. It doesn't affect drivability, but it will keep the EVAP system from passing its checks and from an emissions test.
Symptoms you might notice
- Check-engine light with no change in how the car drives
- Occasionally trouble fueling (pump clicks off) if the vent stays closed
- Failed emissions test
What it costs to fix
Typical range: $50–$300 · about ~0.3–1.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Vent valve / solenoid | $30–$150 | ~0.3–1 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
A vent valve is the common, modest fix; it lives near the rear of the car by the canister, so access is usually easy. Wiring repairs are cheap once located. Sometimes just cleaning debris out of the valve resolves it.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0446 for my exact vehicle →
Frequently asked
Can I drive with P0446?
Yes — it doesn't affect performance or safety. The only practical issues are failing an emissions test and, occasionally, the gas pump clicking off early when you fill up. Fix it at your convenience.
What is the EVAP vent valve?
It's the valve that lets the charcoal canister draw in fresh air and seals the system closed for leak self-tests. Because it sits low near the canister, it commonly gets clogged with dirt or debris, which is a frequent cause of P0446.
How much does it cost to fix P0446?
Usually modest — the vent valve is an inexpensive part and typically easy to reach near the rear of the vehicle. Wiring fixes are cheap, and sometimes just cleaning the valve solves it.
Is P0446 the same as an EVAP leak code?
Not quite — P0446 is a fault in the vent valve circuit itself, whereas codes like P0442/P0455 are leaks in the sealed system. They can be related, but P0446 points specifically at the vent control.
Seeing P0446 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0446 for my vehicleGeneric OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.