MIL light coming on with intermittent buzzer 225 Honda ?

First off I want to thank you guys for all the help in the past posts I drained all my fuel and changed out all filters , a ton of water in the fuel. This was after rebuilding motor over the winter. Finally got the boat running great , twice yesterday after running the boat for a couple of hours I get a slid red check engine light with and intermitting beep .seems to be when I'm idling ? The engine seems to be running great so I just think it may be a loose connection or faulty sensor somewhere but don't want to continue running it this way . Any ideas ?

Pull the codes off the ECM using the SCS service connector as has been described many times on this forum. That code will give you an idea of what sensor is acting up.

Could be as simple as a loose connection, could be working as advertised ... :rolleyes:

When the engine control system detects an PGM-FI malfunction, the PGM-FI indicator light turns on and
the buzzer sounds at one-second intervals.

Just a follow up jumpered out the lime green wire and black wire to give me the codes (24 and 25) ECT2 AND ECT3 sensor . Ended up being the o2 sensor . Motor is running great now , thanks guys for all the help !