I want to use the LSU 4.9 with the "2JZGE NA Header" with EmuBlack

The “2JZGE NA Header” has one “narrow band oxygen sensor” per 3 cylinders (2 total).

If I build an LSU 4.9 with NA, do I wire both of them to the EmuBlack?

Wire only one of them to use?

I would put the O2 sensor further down where it can pick up all 6 cylinders exhaust.
Narrow band sensors are of little use.

I purchased the one pictured.
I would like to install it at the front pipe.
Is there a recommended route that would allow me to get the wires into the car?

A hole and a grommet lol. Can poke a hole in a larger grommet and run it through as well.
Run the wiring and terminate the female connector in the engine bay.