If it rained recently, the ICU might have gotten wet.

"Has anyone else had this issue, could it be as simple as a bad coil, cap or rotor, maybe a hall effect sensor?"

Probably none of those items. Definitely not any of those items will cause a 131.

"Does the Ignition control get an rpm signal from more than one source?"

No, just the CPS you replaced. Other causes are pushed back terminals in the connector where you plugged it in, and I've experienced an out-of-box failure on a new CPS (Bougicord). But you got the 131 from the fuel side, right? Socket 2? The EZK reports this on socket 6 as a 214, but rarely keeps it.

Check for telltale water track out of the rim of the wiper motor grommet.


--
Art Benstein near Baltimore

I'm reading a book about anti-gravity. I just can't put it down.