I'm not sure it's actually removable. Some of the guys on here made it sound like you had to cut it out. You can see if toyota sells it as a part of the stock air box. Besides, you don't really need it unless you live in CA...I think.
Not true. It prevents gas fumes from leaving the closed system (those in the tank are passed to the engine for burning) and entering the atmosphere. The carbon in the filter grabs the fuel fumes and bonds to it. When you start the engine, the fumes are then sucked back out of the charcoal filter and sent into the engine....you don't really need it unless you live in CA...I think.