The vac lines at the other valve seemed fine. Plumbed differently. And also going into something I can't identify. Also, there is a small blue check valve (maybe) coming from said mystery assembly? (passenger side)
And this lives back by the brake booster. One line goes down towards EGR stuff, the other I can't remember. Maybe brake booster.
On FB John said to squeeze off the thick hose to the two valves up front, one at a time of course, and listen for the engine pitch. If the pitch doesn't get higher then that side is blocked or valve not opening.
Does it open via the small vacuum line? They did both hold vacuum.
And is there any way to know the air pump is operating? I guess remove something while it's running?
I've got some more testing to do with this ML based on info above. Any other light that can be shed on this EGR system would certainly be appreciated.....