DTC 172 Insights?

[FLKeysSurf]

Greetings from sunny Key Largo, FL.

2019 G25, H6 motor, 930 hours. Recent sequence of events:

- Smelled gas, found a bad fuel injector, pulled them all for testing/cleaning and replaced a couple that were borderline.
- Next time out I get DTC 172, which most attribute to O2 sensors
- With 930 hours, I decided to replace all four O2 sensors. Also did spark plugs and full 50-hour service
- Took it for a long test run (no ballast, ran different speeds, etc), ran perfect, no codes.
- This weekend went surfing with the family, so full ballast and 11.5 mph.
. -- First rider was 15-20 minutes, boat was fine.
. -- Second rider falls, when boat goes into neutral to go back it throws DTC 172.
. -- Turn boat off/on to reset the code, boat pulls great but when boat goes into neutral it again throws DTC 172
. -- We float for awhile before heading back home, boat runs great but when we slow for no-wake zone we get another DTC 172

Any thoughts on what might be going on, or other things to check for a DTC 172 code?

Thanks for you insights and guidance !!!

[shag]

I don't know if those boats have a high AND low pressure fuel pump like the older ones, but I think that code is related to low fuel pressure.. Wonder if you have a fuel pump going bad... Not sure though.

[FLKeysSurf]

It has low and high pressure pumps. Interesting, most say it is an O2 sensor code, but if the sensors are now good then may be indicating something else. Will research the fuel pressure angle a bit. Thanks!

[shag]

It has low and high pressure pumps. Interesting, most say it is an O2 sensor code, but if the sensors are now good then may be indicating something else. Will research the fuel pressure angle a bit. Thanks!

Whatever you find, let us know!

[FLKeysSurf]

Know it has been awhile, but to close this one out, the dealer finally replaced all fuel injectors and things are good. While checking things out it looks like my "independent service guy" replaced two fuel injectors with incorrect parts, so I made game-time decision to just replace them all instead of just the two incorrect ones.