stock O2 sensor???

[BIG`O]

mods can delete...

[ProECU]

your O2 sensor is located further down towards your catalytic converter.
It is inserted vertically downwards into the exhaust tube, just before the merge collector.

It should be a 4 wire sensor, (2black wires, Green & white - or some similar variation)

There is a school of thought which suggests that you should always insert an O2 vertically downwards, to promote sensor longevity & accuracy, so I am not sure if that bolt you highlighted is for another O2 or a exhast temp sensor.

To insert the Wideband O2, you can remove the stock sensor and insert the wideband + controller.
Depending if the controller simulates 0-1v output(narrowband), you can re-wire it inplace of the original narrowband and use that new narrowband signal for the ECU and the new Wideband output for the O2 meter/display

[BIG`O]

hmmmmm

[ProECU]

Think about your question a bit further...

Hint,
narrowband (0-1v)
wideband (0-5v)

Wideband Meter (0-5v)

Sure you can run it... but whether the output is of any use.....thats another story.