[tripletdaddy]

When I can't get to a metal contact, I learned to insert a sharp sewing pin through the wire insulation or in your case, a pin or other slender metal piece like a stiff wire into the back of the wire connector alongside the wire. I don't think the ground measurement is particularly important, but I like to see if it is close to 0 volts. I certainly would think there is a problem if it is high.

Maybe you didn't catch it earlier, but I'll elaborate more now. To test the egr vacuum regulator, pull the wiring harness off. Then measure its resistance across its two terminals. Normal range is 30 to 70 ohms. Outside that I would assume it is no good. Now you should also check to be sure it is getting proper voltage. So, with key on, engine off, check for full battery voltage inside connector.
It appears the battery pin is next to the bump on side of the connector. The other contact is the signal receiving wire to the computer, so it shouldn't be much if any.