I haven't had evap issues, so I'm not sure (Mr Jacobs here or someone else will hopefully correct me if I'm wrong), but I think you can just disconnect that white harness from the valve. If I understand correctly, that valve, and the vacuum lines, draw vapor from the tank into the intake, so that you aren't venting unburned gas. (I'd have to check the diagram on the driver's side firewall that shows the evap system routing for the vacuum lines-hint hint), but I believe one of those lines comes from the tank.
You've got a strange noise that sounds (reads) like a noisy purge valve, you've got a code, and you haven't figured out what's throwing the code. I don't believe in coincidences, miracles, or lies.
I'd unplug the valve as suggested and see if you still have the noise. If you don't hear the noise, I would run the codes again, write down all the codes and any detailed info you can get, and then post up here.