Okay, you may have found the problem with the vacuum! NICE!!
We need to use the same nomenclature or we'll get confused. A check valve is mechanical. The solenoid in the secondary air system is operated electrically You can see the electric connection at the bottom of the solenoid. Here is a picture:


See the blue collar. That is the vacuum inlet to the solenoid. When the solenoid opens (only at cold starts) it allows vacuum to the yellow collared lines which opens the switch over valves. The switch over valve, passenger side, is in the upper left of the picture and has a gold cap.
In a previous post I asked you to check the vacuum at the drivers side switch over valve by removing the vacuum hose and feeling the vacuum with your thumb. This is at a cold start up with the air pump running. Have you done that?? Do you have vacuum? When the air pump stops running the solenoid should close and thus the vacuum at the switch over valves should not be present. It is explained more in my posts above. Please go back and read my previous posts.

A driving cycle must be completed (some testing requires multiply cycles to be ready for testing). A driving cycle is not how far you drive, but how many times the car has gone through a start warm up and shut down cool off cycle. The EVAP system only works when the PTCM activates it under particular parameters.