Engine Performance problem
2005 Scion xB 4 cyl Front Wheel Drive Automatic 46300 miles

My check engine light is on, I have a code reader, and it says that code 440, 442, and 446 are the proble. The all deal with the Evaporative Emission Control System, I was wondering if this is something I can fix myself or do I need to take the car to the dealer. If I can fix it, what parts I need and what are the procedures.

Thanks Tony Wise