EVAP vent solenoid location?

I recently bought a 2006 Chevy Malibu with a 2.2l engine from my friend. He told me the check engine light was on because of a sensor that has to do with the fuel system. When I plug a code reader into it the code po449 comes up which is the Evap and purge valve. I do not think there is an actual problem with the parts within the system because the code reader also says that my Evap moniter, oxygen moniter, and heated oxygen moniter are not ready. I was wondering if you would be able to determine what possible sensor it could be that is not allowing these monsters to be ready. Thank you.