PMac

My first guess would also be something fuel related. However, most 4 strokes are very voltage sensitive as well so make sure your batteries are good. You can detach your fuel line at the racor and drop it into a 1-2 gallon fuel tank and run the engines off fresh fuel and see if that helps. You may also be looking at an ethanol problem. Keep track of where you buy your fuel as you may find certain mfg. have more ethanol in the fuel than others. Texas has had so many ethanol problems that Mercury came out with an ethanol update kit for the Verados that is pretty much only installed in Texas where it is needed. Check your spark plugs to eliminate the easy stuff first, then try the fuel jug. If the engines have gone into a "safe" mode turning the key off will usually clear it. You may also want to momentarily disconnect the batter cables to make sure the code is cleared. I am betting ethanol or water is your issue. If running the engines on an auxiliary tank clears the problem I would use lots of fuel stabilizer and purchase my fuel at a different location. Good luck.