08 Mobius lsv 02 sensor codes 65567, 65568 response/ frequency

[mikepo26]

purchased boat last year, had some growing pains, has 460 hours, marina put new head on port side when I bought it and 2 new manifold/cats this spring along with new 02s and reprogrammed out the cat temp sensors, anyway check eng light keeps coming on for o2 sensor response time, I did remove the new indmar sensors and they covered in carbon, marina said a tank of new gas should fix it. I am an auto tech and it looks like the engine is running very rich. I have a mid level rinda scan tool, no codes for rich or lean or misfire codes. any help would be appreciated, I am not taking back to the marina I purchased it from, I have lost faith. if there are any Moomba boat techs I would love to hear from you guys too
thanks for the help
mike

[chawkphil]

Haven't had this problem on a boat but in my experience as an auto tech the slow response codes are almost always caused by an exhaust leak somewhere upstream of the o2 sensor

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[CraigXLV]

I had the same codes for both post cat sensors causing the CEL to stay on. I cut the wires and soldered the same 470 ohm 1/2 watt resistor just like in this video and my issue was resolved. If you do this be sure and disconnect the battery afterward to reset the computer. My light has not been on since. Got the resistors at Radio Shack.
https://youtu.be/Ioo0sEUUjLM


Craig

2008 XLV Gravity Games

[CraigXLV]

BTW, video is for a Mastercraft with Indmar engine but did this on my 08 XLV with the Indmar 340 HP.


Craig

2008 XLV Gravity Games

[Poison]

Which one of the Rinda tools do you have? Was it expensive? I've always wanted one of those. I have a finicky check engine light.

[CraigXLV]

I do not have a diagnostic tool. I had a dealer scan mine to find out what codes were showing.


Craig

2008 XLV Gravity Games

[mikepo26]

the marina supposedly reprogrammed the cat monitors out. Moomba had a software update

[mikepo26]

I purchased a tech mate pro last year. work good for clearing the check engine light and good code description but I shouldn't be clearing a code every time I go out. the dealer installed new cats a few weeks ago, I don't hear an exhaust leak. any one having fuel pump/ regulator issues? I love working on my boat mid season on my vacation.

[chawkphil]

You'd be surprised at how a tiny exhaust leak can cause slow response codes. Definitely doesnt need to be so bad that you can hear it. If you have access to a smoke machine you can check the exhaust system that way. Are there codes for both banks or just one? With all the exhaust work you've had done it wouldn't surprise me one bit to see a small leak somewhere

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[mikepo26]

both banks o2 sensors black carboned over thinking I may have deeper concerns