Scott...I said to have him work the pintle aka moving part of the egr right there at the bottom. if it won't free up..snag one at the JY too.
Personally.. the flow issue not being detected.. well it would be detected by the map. if the map is bad..you see the issue. Plus if the EGR pintle is stuck open that could be adding flow and masking flow.
MAF, MAP and EGR are what I'd aim for.