Hey everyone!: I'm selling my thunderheaders and someone sent me a response asking me what size does it have the o2 spots on it? Does anyone know what he's talking about?

 

He is asking what size the bungs are where the O2 sensors plug into. If you have an efi bike they will have the sensors. Not sure what size you have though

 

Thank you for your response.
I don't have efi so still not sure what bungs are. I just got my first harley a couple of years ago so still don't know much about it.

 

Basically it is a well that O2 sensors screw into. The O2 sensors read the amount of oxygen in the exhaust and sends a signal to the computer and then controls the settings to make the mixture right. If you don't have an efi bike then you shouldn't have the bungs. They are usually up near where the pipes connect to the head. Even if you have EFI you may still not need the sensors, but thats a whole new discussion.