All your tests are right on, so it doesn't sound like the EVR is the problem. Check the EVP - the sensor on top of the EGR valve - that is what the code is for. Check the signal voltage from that and check the reference voltage. If you have a Chilton manual, then those tests should be in there as well. It could also be a break in the vacuum system between the EVR and the EGR valve.
I did start with the EVP test per the book and it passed at that time.
When I did the vacuum test I disconnected the rubber connector from the EVR and plugged the vacuum side of the rubber connector and connected a short length of tubing and an inline connector right to the rubber EVR vacuum connector opposite the green line to EGR and created vacuum straw in a milkshake style put my tongue on the end and waited a minute to see if it held pressure testing both the EGR and the vacuum line at the same time. Good to go from there I thought.
Since I posted I did find a leak in the vacuum system it was near the air bypass valve, close the manifold . Melted, and collapsed on the back side where you could not see it (of course). That brought up my vacuum pressure some since they share a common vacuum supply line. Then I disconnected the battery for ten min and reset the system. The 327 MIL code came back after it warmed up.
I have the old EVP (I replaced with a new OEM during the rebuild) Ill test it and swap them just for kicks. It is easy enough.
Well that did it!
On retest the EVP failed the diagnostics.
However the Old Part is in fine working order and my problems are gone