Kind of know the answer but here goes...

So here's the deal... 2014 f-350 6.7, 186202 miles. Check engine light on with P0401:00-EC in the PCM EGR flow etc.. Same with the OBDII via Forscan. Called the dealership ( Power Ford, Newport Oregon) told them what i found and they asked how I determined that the EGR Cooler needed to be replaced? I told them that at 186000 mi all OEM with no previous work done on the engine and the fact that the coolers are prone to be the cause of P0401 code, they said the Mech wanted to "lay hands" on it themselves to make sure that was the problem, not wanting ME to throw money at parts and labor for something not needed. at $140 to diagnose I was willing to accept, 2 hrs later they came back and said that the EGR Valve was bad, HUH! Replacement cost $ 972.85 Well S*it, I said to myself and against my feelings that they were going after the wrong part agreed to the work. Fast forward 2 days and 55 miles TADA check engine light and the P0401. Went back to see what could be done and they said would need to put on the scope again in the morning 0800 guess i will see what they come up with, any suggestions?

BTW have the old valve in hand, Doesn’t seem to be anything visually wrong ie: valve seats are pretty clean mechanically opening and closing, any way to bench test the valve?