Knock Retard At Limit - Error Message

[GMLIII]

Just wondering if someone could help me out with this error message. I'm assuming it is a faulty oxygen sensor? I usually just hit ignore and keep driving but the error message is occurring more often now. Once I find out what is wrong , I want to let my dealer know so he can order the part before my boat goes out of warranty which occurs in another 18 hours.

[Peter6000]

Knock usually happens when ignition advance is to much, but your controller should not do that at all.
Could be a bad spark plug or ground connection. I have never seen a knock sensor putting out to much signal if the break the usually go dead.
Could be the gas but I would say unlikely.
Bad o2 sensor would trigger different error.
Knock is serious I would not drive it.
Do you hear knocking noise from the engine under load?
I would get it to the dealership before the 18h expire and call them and explane.

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[NautiqueJeff]

I was going to ask what gas you're running.

Probably easiest thing is to have someone use a Diacom and see what's happening.

[GMLIII]

I was going to ask what gas you're running.

Probably easiest thing is to have someone use a Diacom and see what's happening.

Don’t think it is gas . I burn 87 non ethanol from same marina all day long . Will do what you said and another poster from another site stated they replaced knock retard and all good now

[GMLIII]

Findings - At the end of the day, the dealer said one of the spark plugs was miss firing causing the error. The dealer changed out my spark plug and said I was good to go. He said if you do a lot of surfing which we do, it will cause deposits to build on the plugs. In addition they recommend changing the spark plugs around 500 hours anyway.