What does po446 code mean on the chevy impala?

When a Chevy Impala returns a P0446 trouble code, it means there is a problem with the evaporative emission control (EVAP) system. In most cases, the the EVAP carbon canister isn't getting enough fresh air because of a blocked vent solenoid. The EVAP systems stops vapors from escaping. Charcoal pellets within the charcoal canister absorb and store these vapors. The engine control module controls the vent control valve, which lets air flow into the canister to push the vapors into the air intake of the engine. If a P0446 code has been given, a short in the circuitry has been detected by the ECM during a leak test. A few symptoms You may experience along side this trouble code is a check engine light on, gasoline smell, and decreased fuel economy. A loose or broken gas cap is the most common cause. If You have to replace the evaporative canister, it will run You between $590 and $700. Labor accounts for about $200 to $270 of that total.