Honda 50 cv EFI engine fault codes

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Hi everyone, I'm new here and I'd like to know if there is someone who has the 50 cv EFI fault codes. My Honda 50 cv EFI is running fine until the MIL comes up and starts to buzz. Could it be the oil change interval? We remove the fuel tank due to dirt and water on in, we cleaned all of it and place a new fuel filter to ensure the petrol goes clean. I'd appreciate very much your help.

Thanks
Andrés