Adaptive-learn gasoline bank2 low?

I was running my 2012 Sunsport 242 w/ 6L Indmar pretty hard wake surfing and then pulling tubes when I got the following diagnostic message:

Attachment 18159

(in case the picture doesn't load, it's DTC:175 Adaptive-learn gasoline bank2 low SPN: 4239 FMI 1 Plug ID B)

This has happened twice so far, each time at the end of the day after working the boat pretty hard. On the second occurrence, I was able to put my hand on the driver side exhaust riser, but not on the other side because it was too hot. After turning it off and letting everything cool down, it started back up and I didn't have any other problems the rest of the trip to the dock. Other than the warning, the engine acts, sounds, & revs normal. If I hide the message or turn the boat off, it doesn't continuously re-appear. Is this something I should be alarmed about?

I don't know much if anything about you boat but I believe your boat has catalytic exhaust. I would think that the risers running unusually hot will affect the cats and could cause a lean code. Kind of like a bad o2 sensor in a a car exhaust will cause a lean code. There are other things that could to I just don't have any real world experience with your set up to know for sure.

I would look into the hot riser first. You should be able to put your hand on it without extreme discomfort

Thanks for the input - I took it out yesterday and took it easy (we would wake surf and then take a "water break" letting everything cool down) and no codes! The risers are still getting hot, but I was able to uncomfortably touch them for a few seconds without getting burned. My engine temp sensor shows just under 175 while pulling, and there doesn't appear to be any leaks from the wet exhaust hoses leading to either of the risers. Is there something that would keep my engine in the normal range, but restrict flow to the risers? I am towing with full ballast so the exhaust tips are pushed down pretty far during idle.

It would be from reduced water flow which could be a couple of things. The first thing would be the impeller in the raw water pump. They can loose their elasticity over time and still pump water just not quite enough to do the job. If you have closed cooling there could be some blockage in the heat exchanger from sand or some other debris sucked up by the raw water pump. Like I said in the previous post I don't know all of the details about your boat but the cooling systems are generally simple. Look for any obvious area that could restrict the water flow. kinked hose, cast iron fitting that could corrode and cause a restriction, simple stuff like that. But I would definitely start with the impeller.

I was out again today and I got the code once but nothing after. So, I checked extensively for leaks, kinks, or other restrictions and everything looks good. According to the dealer, the impeller was replaced at 96 hours and the boat now has 110. I don't know if this makes a difference but it's hottest right next to the 2nd O2 sensor. Before the sensor you can touch. I'm starting to think the riser is blocked near the sensor.

At this point I can't really help you very much. You could have a problem where the bank is actually lean and that is causing the catalyst to run hot or the manifold is running hot causing the o2 sensor to show a false lean condition. In the second situation the fuel system will pump more fuel into that bank of cylinders possibly damaging the catalyst. But these are just very general guesses.

I would try to find normal operating temperature ranges for the manifolds and risers and check exactly what you have. I would think Indmar would have a good idea if you have a normal temperature at the o2 sensor and a reason why the temp would be high at that specific area. Good luck and I hope you don't need to replace the manifolds.

Thanks for the help - I'll keep an eye on it for now.