A lambda sensor needs a hole in the exhaust and a nut welded
on top of the hole.
Then connect the sensor to the air/fuel gauge.

The sensor could be non heated, this one needs to be near
the exhaust manifold because the sensor needs at least 400 degrC
to work properly.

The sensor could carry a heating element, in which case
the sensor could be placed further down the exhaust.

Most advanced option (and most expensive) is a wide band sensor.

I don't think you need a wide band sensor, the sensor just
measures the O2 in the exhaust gasses.
Before the wide band existed, engine management
systems worked very well with the other types of sensors.

So I guess any lamda sensor could do the job, they do need
to be in good working order of course.

Cheers.