I have a 2002 Sienna with a Check engine code of P0440. I have replaced the Gas Cap but the code still persists. I have seen some post about CCV needs to possibly be replaced. Any Ideas on how I make sure this is the right part?

I would bet that CCV is the culprit. Most get broken by pulling on the air filter box because the hose isn't long enough.
The canister on yours is a nesting ground for spiders and mud dobbers? <sp>? Seen that many times.

I was looking for the part on-line. Is this the same as a Mass Air Flow sensor?

No, MAF is air induction, and CCV is emissions. Two totally different