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Q: can anyone help i have a avalanche and the engine light is on the code is p0446 on 2004 Chevrolet Avalanche 1500

so far nothing has happened ...i was told that it was to due with the sealed fuel system ??....can anyone give me any info on this???
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evap code. you need a shop with a smoke machine, scan tool and volt meter to determine the failure.

Tests/Procedures: 1. Loosen the gas cap, check for about 1.5 volts or 0 inches H2O pressure on the Fuel Tank Pressure Sensor (FTPS) using a scanner.

2. Check for a restricted evaporator vent solenoid filter. Remove the vacuum hose from the vent solenoid.

3. Install a longer hose to the vent solenoid fitting and attempt to blow through it with your mouth. There should be no resistance. If there is, the vent solenoid is restricted and should be replaced.

4. If the vent solenoid is not restricted, check for a restricted charcoal canister.
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