2019 g23 issue

[JL19GTHANG]

boat runs good 95 percent of the time. however smetimes (only at idle) the boat will shut off and throw 2 codes, spn 3225 FMI 10 AND SPN 67063 FMI10
DTC 8915 o2 sensor 1 pump cell slow to warm up
DTC 8933 02 sensor 2 pump cell slow to warm up
any help with this issue woulb be greatly appreciated! thank you!!!

[jpwhit]

Those codes aren’t likely the cause of your engine shutting off, but more likely a side effect of the problem that’s causing the shutdown. Especially given that you’re getting the codes for both O2 sensors simultaneously and only when the shutdown occurs. They also aren’t codes that would cause the engine to shut off. They are basically saying the O2 sensors aren’t warming up quickly enough. They can be caused if there is low voltage to the sensors. So I think you’re having an electrical system problem that is causing the engine shutdown and those codes. Unfortunately this kind of problem can be difficult to diagnose given the intermittent nature.

When the problem happens, do you see any other signs of low voltage such as anything on the dash or stereo system acting strangely. That can help figure out if the problem is in the boat wiring harness vs being in the engine wiring harness. Otherwise, one approach is to setup some voltage logging equipment at key points in the system. Another approach is to just start going through the wiring harnesses and connectors looking for any poor connections.