O2 Sensor Cleaning - Improved engine RPM/Performance

[rost5501]

I had an engine alarm (for a week or so) and after scanning with CanDoo Pro I came up with a code for the first O2 sensor on my 2013 242 LS - port engine. So I purchased a replacement sensor and decided to pull all four O2 sensors to make some comparisons. FYI - engines have 190 hours on them.

The O2 sensors come our pretty easy; release a zip tie, unclip the wiring connector, then unscrew sensor with 17 mm wrench. All four sensors ohmed out to the same values with a multimeter. Was a bit surprised the "bad" sensor had the same readings, but could be the heating element is going out on it (or it was not bad at all). There was minor carbon buildup on all 4 sensors, so I sprayed them with engine degreaser, let them sit for 30 minutes, then sprayed them again with carb cleaner. Wiped them down, dried them off, and reinstalled three old sensors and the new one with a bit of anti-seize on the threads.

Cleared the code and then went for a test run and my engine alarm was gone. Boat ran nice and smooth, like it always had (even with the alarm). I was surprised to see that I was able to get 7,000 RPMs out of the both motors. Previous to this I only had 6,800 RPMs (even with out the engine alarm). I have owned the boat for 3 seasons and just thought that 6,800 RPMs was the normal top end.

Ran the boat a few times this past weekend and was still getting 7,000 RPM. I guess the O2 sensors had some excessive build up on them and this is why the RPMS were down.

Thought this information was worth sharing on the forum. May be be worth cleaning O2 sensors to see if a code(s) goes away or as a maintenance step every few years.

 

[FSH 210 Sport]

Great post!

If you have the 1.8L engine you should be getting at least 7400 rpm unless you’re at a higher altitude. Have you changed plugs, and or checked your air filters for oil saturation caused by too high of an oil level? Also check to make sure that the sound insulation is secure in the engine bay by the air cleaners, don’t just look at it pull gently on it to make sure it can’t move while the engines are running. We’ve had a few owners who found had this insulation loose and it was moving over and blocking the air intake under higher power.

 

[rost5501]

Great post!

If you have the 1.8L engine you should be getting at least 7400 rpm unless you’re at a higher altitude. Have you changed plugs, and or checked your air filters for oil saturation caused by too high of an oil level? Also check to make sure that the sound insulation is secure in the engine bay by the air cleaners, don’t just look at it pull gently on it to make sure it can’t move while the engines are running. We’ve had a few owners who found had this insulation loose and it was moving over and blocking the air intake under higher power.

Surprised there is still that much more RPM to gain. I do not suspect I will gain much more "performance" from the boat if I do gain more RPM. I am not really looking to push it to the limits. Plus it is usually too choppy on Lake Erie for me to maintain higher speeds for any period of time. 44-46 MPH is the top end on a calm day and I am happy with that.

I have changed the plugs every year (and gapped them), inspected and blew out the air filters every year as well. FYI - very minor amount to be cleaned on the air filters, usually next to nothing to clean on them.

As I recall there is no sound insulation on the front wall of my engine compartment and the insulation on the hatch is pretty solid. But I will look at this closer this weekend.

Thanks for the insights.

 

[GoodCubanito]

I had an engine alarm (for a week or so) and after scanning with CanDoo Pro I came up with a code for the first O2 sensor on my 2013 242 LS - port engine. So I purchased a replacement sensor and decided to pull all four O2 sensors to make some comparisons. FYI - engines have 190 hours on them.

The O2 sensors come our pretty easy; release a zip tie, unclip the wiring connector, then unscrew sensor with 17 mm wrench. All four sensors ohmed out to the same values with a multimeter. Was a bit surprised the "bad" sensor had the same readings, but could be the heating element is going out on it (or it was not bad at all). There was minor carbon buildup on all 4 sensors, so I sprayed them with engine degreaser, let them sit for 30 minutes, then sprayed them again with carb cleaner. Wiped them down, dried them off, and reinstalled three old sensors and the new one with a bit of anti-seize on the threads.

Cleared the code and then went for a test run and my engine alarm was gone. Boat ran nice and smooth, like it always had (even with the alarm). I was surprised to see that I was able to get 7,000 RPMs out of the both motors. Previous to this I only had 6,800 RPMs (even with out the engine alarm). I have owned the boat for 3 seasons and just thought that 6,800 RPMs was the normal top end.

Ran the boat a few times this past weekend and was still getting 7,000 RPM. I guess the O2 sensors had some excessive build up on them and this is why the RPMS were down.

Thought this information was worth sharing on the forum. May be be worth cleaning O2 sensors to see if a code(s) goes away or as a maintenance step every few years.

Thank you very much for such a detailed explanation... I will follow up your recommendations... so, you said 4 O2 sensors? I thought there were only 2... also, where can I get that scanning tool?

 

[rost5501]

The first oxygen sensors is upstream of catalytic converter second is downstream.

I purchased the scanning tool from their web site: CANDooPro - Yamaha Tool [1200] - $449.00 : Zen Cart!, The Art of E-commerce