Evaporative emissions (EVAP)
P0446
Evaporative Emission System Vent Control Circuit Malfunction
What does P0446 mean?
P0446 means the engine computer sees a problem with the EVAP vent valve or its wiring. The vent valve lets fresh air into the charcoal canister and seals the system for leak testing. When it sticks or its circuit fails, the computer cannot run that test and sets this code instead of a leak code.
Can I keep driving with P0446?
Low urgency
Not a safety issue. The main day-to-day symptom is the emissions failure and the occasional slow fill-up at the pump.
Symptoms of P0446
Check engine light with normal driveability
Occasional difficulty getting fuel to pump in at the station
Failed emissions test
Common causes of P0446
A vent valve seized by dirt, corrosion or road debris
Damaged wiring or a corroded connector at the valve
A blocked vent line or a contaminated charcoal canister
A failing vent solenoid
These are ordered roughly by how often they turn out to be the cause — but the code names a system, not a part. Confirming which one is yours takes data from the running engine.
What does it cost to fix P0446?
$100 – $500
Typical US independent-shop range, parts and labour included. It is wide on purpose: the cheap end is usually a sensor, a hose or a cap, and the expensive end is the major component the code was reporting on. Which one you need is a diagnosis, not a guess — and dealer rates run higher than these figures.
What does P0446 mean for your car?
This page explains what P0446 means in general. It cannot tell you which of those causes is yours, because that answer is in your car's own data. Kaiju Mechanic reads the codes your car is actually storing, plus live sensor data through any standard ELM327 adapter, and interprets it against your exact year, make, model and mileage. You can also just ask it about P0446 in chat — no adapter needed for that.
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