Cutlass running rough need help

[airboatgreg]

EGR still my bet.
I think you are going down the rabbit hole on the wires for this issue
best bet at looking at wires without an oscilloscope is inspecting both ends for corrosion and arcing and looking at he exterior of them for insulation breaks and being rubbed thru or burnt by the exhaust. Take a spray bottle with some soap and spray them, especially the boots to see if it misses or you see arcing

 

[Clone TIE Pilot]

May want to check for excess distributor shaft wobble from worn bushings.

 

[ChetC]

Went for a 300mile trip to the family cottage and back home with no issues. Went ahead and put new EGR valve on it today just for precaution. Thank u everyone that chimed in, very much appreciated!