Trouble code
P0446
Evaporative Emission Control System Vent Control Circuit
What P0446 means
The vent valve that lets the EVAP system breathe is not responding correctly.
Symptoms you may notice
- Check engine light
- Sometimes difficulty filling the tank
Common causes, cheapest first
- Failed vent valve
- Blocked vent filter
- Wiring or connector corrosion
- Spider or debris blocking the vent line
Before you buy anythingThe vent valve usually sits near the fuel tank and takes road spray, so corroded connectors are common. Check the connector before condemning the valve.
What to do next
- Confirm the code with your own scan tool, or have it read free at a chain parts store.
- Decode your VIN so you know your exact engine and build date.
- Work down the causes above from cheapest to most expensive.
- Search NHTSA for a recall or service bulletin covering this symptom on your vehicle.
- Read the engine buying guide before ordering.
P0446 is a generic OBD-II code, standardized across every make and model sold in the US from 1996 onward. The meaning is the same on any vehicle; the specific part and its location are not.
Parts
Parts commonly needed for P0446
These go to Amazon. We earn a commission if you buy, at no extra cost to you — see our affiliate disclosure. Which one you actually need depends on diagnosis — read the note above first.
Confirm fitment against your VIN on the listing page before ordering. A part that matches your year and model can still be wrong for your build date or engine code.