The EFI update went fine. Did the SIP disable in El Capitan in a Mac Pro 4,1- Result 5,1. Fine. Figured out the cause. One of the very, very tiny pins for some reason got bent on the periphery of the center of the CPU (on the processor tray). I was very careful- So I can not for the life of me figure out how this happened. After attempting to straighten the pin and booting up I got only 1 RAM slot not working. 3 is much better than 1 working. I took it apart about 4 times and I got the same result. They are very fragile and so small- I needed a jeweler's loupe to do the job. I didn't want to chance it another time. It being a back up Mac Pro- I'm accepting this problem. Bought more RAM - so I making up for the lost slot. Thanks for your answer.