Thank you for the reply. Since my boat is in the water and I don’t have a place on land to work on it, I’m going to take it to a Honda mechanic. If the heads have to come off, that would be easier to do on land.
With the key on and the engine off, the oil pressure alarm sounds. I shorted the service port per the diagnostic procedure and the code came back 26. Could a continuity break in the loom to the dash panel cause the fault? Or does the ecm record the fault from to sensor to the ecm?