2021 g23 Warning Message

[kodiak]

I have a 2021 with the ZZ8 and this warning message keep popping up yesterday, I was unable to go over 4 or 5 mph. If I shut off the Motor and restated the message would go away, but would come back if I idle for a long period of time.
Would not happen during wakeboard or surfing.

[zmnypit]

o2 Sensor maybe?

[BT]

Lean fuel mixture bank 1. On GM engines that is usually starboard side for a v-drive. Lean is either not enough fuel or to much air. Since it seems to be lean at idle from your description, I would guess a vacuum leak. An exhaust leak near an O2 sensor or a lazy O2 sensor can also cause the code. Usually the computer will flag a different code if it is a faulty sensor though.

With diagnostic software you can see live fuel trims which helps troubleshooting greatly. You can use propane around suspected vacuum sources and watch fuel trims respond when the propane is sucked into the vacuum source. You also determine if the O2 sensor is reporting lean or rich accurately. Probably easier to let a shop troubleshoot. Fuel pressure or fuel contamination is also a consideration, but fuel trims would be affected lean under a load more than idle. That is where live data is helpful.

What lake are you on? I live on Martin and surf nearly every weekend when able. Nice boat you have there.