Where to mount wideband O2 sensor.

Also if you want to save "a bit" of money and if you have access to a fasteners store, most O2 sensors are the same thread as an 18mm (Ford style) spark plug. I'd have to look that up. It is possible to order hex nuts this size, and they are a HELL of a lot cheaper that all the bungs everybody is selling.

And of course that points out ANOTHER little tidbit, which is, if for some reason you feel the need to run without a sensor...........18mm plugs are cheap LOL