You can do an EGR Flow test with a hand vacuum pump.

You attach it to the egr port and pull at least 12" of vac with engine at idle and coolant at normal temp. The car should attemp to stall/run rough with egr open. If not , then you have egr tube blockage .
You also want to hear the egr Snap shut when you release the vac supply.
EGR never gets vac @ idle or full throttle.

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A Dalton