[ImperialCrown]

Welcome to Allpar. I doubt that it is related to the ignition switch or clockspring. I would more suspect underhood connections or wiring problems. Possibly one or two wiring connections causing all your injector/coil switching problems. Maybe an intermediate connector or PCM-related connector?
You may have to have it acting up in order to find it. Try a wire/connector terminal 'wiggle' test while it's idling? Check all PCM powers and grounds?

 

[ImperialCrown]

Yes, I have been burned before by deciding prematurely that the PCM was bad. There is no direct test for a PCM and all supporting electronics have to be ruled out first.
There are 'possible causes' lists for each of the fault codes and it is good to see which possible causes they share in common to solve a problem first. In the 'trouble tree'-type diagnostic methods and procedures, the PCM is always the last house on the block.
I'm glad that you solved it.