I posted all the trouble tree info you should need to figure out your P0441 it's probably just a bad vent solenoid. Let me know what you find.
The evaporative system reduces hydrocarbon emissions by trapping fuel tank vapors until they can be burned as part of the incoming fuel charge. Evaporating fuel is stored in a charcoal canister until it can be flushed into the intake manifold.
The evaporative control system is made up of the following components:
1. Fuel tank, fuel/vapor separator and fuel tank pressure sensor.
2. Canister and canister close valve.
3. Purge control valve.
In normal operation, the purge control valve opens and closes depending on throttle angle and intake manifold vacuum. When it opens fuel vapors are flushed from the canister and drawn into the intake manifold. To avoid a vacuum build-up in the canister, the canister close valve in normally held open to allow fresh air to replace the vapors drawn into the intake manifold.
The leak test is completed in three steps.
1. To draw the system down to manifold vacuum, the canister close valve shuts and the purge control solenoid valve opens. The fuel tank pressure sensor monitors the rate at which pressure drops in the system.
2. The fuel tank pressure sensor now monitors how well the system holds the vacuum. The purge control solenoid valve closes, completely sealing the system.
3. At the end of the test, the canister close valve opens and the purge control solenoid valve returns to its cycling mode. If the canister close valve is stuck closed, the fuel tank pressure sensor will see that the system remains under a vacuum and code P0446 is set.
Note that water or other debris in the line between the purge control solenoid valve and canister can also set code P0446. If the purge control valve is stuck open, code P0445 may be set. To clear lines of debris, blow compressed air through the lines.
Images (Click to enlarge)
Saturday, January 8th, 2011 AT 6:36 PM