[csaxon]

All 3 of those evap codes together means a gross evap leak and usually it’s a loose gas cap, BUT, when checking the air filter, the line going to the canister closed valve vacuum switching valve on the side of the air box sometimes comes loose.

Toyota also issued a TSB covering all 3 codes for your model year. They developed an updated canister closed vacuum switching valve.

 

[toyomoho]

Leak or a bad VSV valve. Often gas cap, vacuum line in the EVAP system clogged/leaking., VSV valve or canister leaks. The Toyota service manual has a good section on the EVAP system and codes. Also check out the Camry TSB. This year of Avalon also had a TSB for the P0441/P0446 combo codes.

http://oregonstate.edu/~tongt/camry

 

[skewe]

check ur cables and hoses.
i replaced mine and the whole 9 yards cos of the same codes.
search for my ID and you will see what I did.
Changed EVAP and charcoal canister

They found out later that it was a hose that was lose in the engine bay