P0446 means the ECU has detected a problem with the EVAP vent control circuit. The vent valve controls airflow through the charcoal canister that captures fuel vapours. When the valve or its circuit fails, the EVAP system cannot properly purge or seal, triggering this code.
P0446 means the ECU has detected a problem with the EVAP vent control circuit. The vent valve controls airflow through the charcoal canister that captures fuel vapours. When the valve or its circuit fails, the EVAP system cannot properly purge or seal, triggering this code.
P0446 is a evap system-related diagnostic trouble code classified as low severity. When your vehicle's ECU detects this condition, it stores P0446 and illuminates the check engine light.
If your vehicle has triggered P0446, you may notice one or more of these symptoms:
Here are the most common causes of P0446, ranked by how likely they are to be the culprit:
Generally yes, for short-term driving. Completely safe to drive. The EVAP system controls fuel vapour emissions and has no effect on engine performance or safety. The only consequence is a lit check engine light and emissions test failure.
Follow these steps to pinpoint the root cause of P0446:
Repair costs for P0446 vary depending on the root cause and your vehicle. Here are typical estimates:
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0446 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
These codes are often seen alongside P0446 or indicate related issues:
Yes, completely safe. The EVAP system only controls fuel vapour emissions. No effect on engine performance or safety. You'll fail emissions testing though.
A solenoid-controlled valve that allows fresh air into the charcoal canister during purge cycles. When the ECU tests the EVAP system for leaks, it closes the vent valve to seal the system. If it can't close or the circuit fails, P0446 is set.
Rarely. A bad gas cap more commonly triggers P0440 or P0455 (large leak). P0446 specifically points to the vent control circuit, not a general leak. But checking the cap first is free and takes 10 seconds.
The vent valve itself costs 30-120 euros. Labour is 40-150 euros since the valve is usually accessible near the rear of the vehicle. Total: 70-270 euros for most vehicles.
Fixing P0446 costs 60-180 euros total to replace the EVAP vent solenoid. Check the connector for corrosion first, as wiring is the second most common cause.
Clearing a code before inspection resets the readiness monitors, and stations check those. Here are the OBD2 codes that fail, and why a fresh clear fails anyway.
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Your car logged P0446. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and shows the €10-€450 repair range so you know the number before a shop quotes you.
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