Hi thank you for your question my name is ***** ***** I am a fully qualified technician with over 30 years in the trade, hopefully I can help you.
Your Honda has two 02 (lambda) sensors, the one that was replaced sounds as though it was the pre-cat sensor, this controls the switching of the mixture and adjusts according to the reading of the exhaust gasses. The second 02 (lambda) sensor fits in the exhaust after the cat and this is there to read the output of the gasses, this reading should remain steady, if it does not it normally indicates either a faulty sensor or that the cat has failed.
The reason for the light may also be one of the other engine sensors and it would really be best to read off any codes with an EOBD code reader before replacing any components.
This will ensure you are looking in the right area. If the code did come up to be the same sensor, I would advise checking the wiring to ensure the light isn't coming up due to a poor connection to the sensor, this is another common failure.
Finally another common cause of the 02 sensor triggering a code and putting up the light is that an air leak is present in the system.
To answer your question as to whether you could replace the sensor yourself, if it is just the sensor I would say yes, if it is this it will not need coding in, and if it is causing the error code this will be cleared when the new sensor is fitted.
I hope this answers your question but do please feel free to get back to me for any further information.
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