Mine, bought in Utah, was a California model. I swapped out the charcoal filter for the little white gizmo when I was troubleshooting a problem. It turns out the mounting bracket where the filter box mounted is perfect for attaching a little hidden container. I have a spare key in there just in case I lock my keys in the trunk while away from home. The charcoal filter doesn't affect performance in any way, so there's no reason to pull it off. If I wasn't using that position to mount the hidden storage box I would put mine back the way it was.
The little white plastic thingy is basically just a little purge tank. If fuel overflows out of the fuel tank it runs through the white thingy and out to the ground via a hose. It also vents something but I don't recall what.
I left the electrical connector attached to the purge valve but even that isn't necessary. It doesn't throw fault codes either way.