Honda 2010 bf40 intermittent beeper alarm, check engine light. O2 sensor problem?

I have a 2010 Honda BF40D (BBDJ-1006407) 4 stroke EFI which I am using in a salmon fishery in rural Alaska. It has four indicators on a little panel on the handle: oil pressure, battery, temperature, and engine. Ten minutes after starting, the check engine indicator comes on and I get an intermittent beep, one second beep at one second intervals. I had a loose fuel fitting which I tightened. The check engine indicator remains red and the beep continues. Do I have to reset the system? Disconnecting the battery cable did not reset. Turning on the ignition key and manipulating the kill switch five times in 20 seconds did not reset. Do I need a SCS service connector (070PZ-ZY30100) to reset the warning indicators? I am ordering a service manual for this motor. The motor has less than300 hours on it. I use a large on line water separator mounted on the transom. I do not think that I have fuel contamination problems. Could it be the O2 sensor?

Get the service connector. You can use a paper clip, but there are 4 wires and I am not sure which two you should short. I do not want to tell you the wrong ones.

When you plug it in, then the red light will flash a "morse code" long and short lights. long is 10 1 short is 1, 2 shorts are 2, etc.

Then look up in your manual ( when you get it) what may be causing the problem.

You can only reset the codes with the service connector in place. Then you do the kill switch routine (5 times, etc).

We do not have a 40 in the shop, but we do have a 90. I will try to remember to check tomorrow....they may have the same colors. Then, at least you can start trouble shooting.

Mike