I have a 2008 Baja outlaw 23,with a 496 mag I have a random constant beep that lasts for about five seconds. It won't take any throttle while the beep is on but once it stops it runs fine. On the way back to the house at wot it would cut out like you turned the key off but once the tholrottle is pulled back it come back to life. Please help.

Constant horn not intermittent correct ?

IMO its the shift switch in which could be the switch is out of adjustment or bad. it also could be related to a wiring problem to it (shift switch) or a mechanical linkage problem telling the PCM that you are still in N while really in gear. Anyways IMO I think the shift switch is out of adjustment as try that because it will be the easiest to check right off the bat.. Also it would be wise to get the motor scanned to help pin point the problem 4 sure and look into the fault history to see if any other spec is out of range or faults showings..

Tough without a scanner, but I will throw my guess out there. Something very close to what you describe happened to me once with a 6.2, turned out it was a bad wire in the injector harness. With boat in water or on hose wiggle every wire and connection to try to duplicate.

cut the wires that go to the beeper...

I had the same issue with one of my engines. Turned out to be some marine life on the raw water pressure sensor. The beauty of that engine is EVERYTHING is obvious with a scan. Get a laptop to it and you'll know everything.

I'm ordering the adapter to get all the engine data on my Garmin display.

Does that work without the NMEA2000?

Post some part numbers. I would like to do that too.

The adapter is to go to NMEA2000 that the Garmin wants. "SmartCraft-NMEA2000 Gateway" Part# 8M0065208

Water pressure sensor fault should be 2 beeps every minute but sometimes these computer control engines do things out the realm. As everyone said without scan it is really a guess.

I still say shift switch out of adjustment or its bad or wiring to it or last but not least linkage problem.

The deal with the shift switch is it can cut your engine off or reduce power down to 5 % if the switch is out of adjustment or bad because it will indicate (input to the PCM) being in neutral at high speeds and or high loads.

No way to tell without a scanner. www.rinda.com It's the best $500 you will spend on your boat; and has been discussed on here many times.