If you are getting the obd-ii Code P0440, P0441, P0442, P0446
Please follow:
1. Make sure the gas cap is ON (and “clicks” ) and is the correct Toyota Gas Cap (aftermarket may not work). Clear the codes and run for a while. See if codes come back.
2. Make sure the tube to the electrical valve on the air cleaner is still on – Many clumsy oil change places pull these off accidentally (or on purpose- who knows?)
3. Test and inspect all the rubber lines under the hood and connecting to the canister.
4. Test the VSV Electrical valve on the canister – put 12V across it using 2 small alligator clips and wires (RadioShack) It should click and let air through.
5. Test the other 2 valves under the hood the same way (the one on the air cleaner works backwards i.e. Power = Block Airflow)
6. If you can – test the air valves (seen above) –
7. Bend over – get your wallet out and buy a new Charcoal canister – ouch! $300+ If you are still getting the “whoosh” on taking the cap off, maybe the Pressure sensor in the tank is bad.