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2011 BF225 HO2 sensor and ECM replacement

jacky2942

New member
My 2011 BF225AK1 with serial number BAGJ1600049 has repeating O2 sensor failure and weird continous buzzer issue only at certain RPM range between 4K-5K. When the buzzing sound is started around 4K rpm, there is no other issue other than the buzzing sound. If the throttle moves any direction to change the RPM up or down, the buzzer stops. The engine works fine. Only the high pitch sound is annoying.

I suspect that the ECM is the culprit because it has 34750-ZY3-C01 ECM installed with 35655-ZY3-013 HO2 sensor which has 22mm big spanner.
The SB71 showed that it should be replaced with ECU Kit 06347-ZY3-317. So I bought this kit and found this kit come with 35655-ZY3-C01 HO2 sensor with 14mm spanner.

Since my motor's manifold has 22mm socket for HO2 sensor, I can't use the 14mm sensor directly. Can I just use the adapter 90074-ZY3-305 to use the smaller HO2 with the new ECM? or Can I just change the ECM and use the 22mm existing HO2 sensor?

Or do I have to change the manifold with new 18120-ZY3-C01ZA manifold that come with 14mm socket?

The reason that I think the ECM is the culprit is the alarm(or buzzer) is not activated for the first few minutes after I changed HO2 sensor. I tested it two times with a two new HO2 sensors.
 
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Send me an e-mail at [email protected] and ask me to return Honda SB #70. (It's too big to upload on this site.) That straightens out what ECM goes with what HO2 sensor.

The adaptor for the 14 mm HO2 sensor is part number 90074-ZY3-305.
 
Send me an e-mail at [email protected] and ask me to return Honda SB #70. (It's too big to upload on this site.) That straightens out what ECM goes with what HO2 sensor.

The adaptor for the 14 mm HO2 sensor is part number 90074-ZY3-305.


Thank you for the document.
Since my BF225 is AK1, it is supposed to replace with ECM 34750-ZY3-C02 and HO2S 35655-ZY3-C01 according to SB71.

Also BF225AK1 is supposed to have Manifold 18120-ZY3-C01ZA which has 14mm socket for HO2S, but the manifold equipped in my BF225 is 1
8120-ZY3-010ZA which supposed to be equipped with BF225AK0 model. I bought this motor last year and don't know if previous owner changed the manifold.
Should I just install the ECM 34750-ZY3-C02 and HO2S 35655-ZY3-C01 with the adapter 90074-ZY3-305?
or do I have to also change the manifold to 18120-ZY3-C01ZA to use the ECU HO2S Kit recommended by SB71?
 
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