Lean idle. Rich cruise.

I agree

my use of modern was to cover lambda sensors produced for OEM use by big players in the supply chain

rather than the older narrow and wide band sensor that were produced to work with a very specific ECU or gauge system which were quite rightly bespoke jobs for the application in hand.

since then they have become almost universal fitment and its a damn sight easier to just standardise the sensor than it is to tweak the software on every ECU

its a bit like the original OBD set up with its manufacturer specific plug and codes and the eventual closer standardisation of OBDII

every car has its own unique codes but the majority applicable to all cars in the range or indeed across car companies using an ECU from a supplier common to both will have a reasonable amount of standardisation. you can now buy a code reader that works reasonably effectively across a wide range of manufacturers rather than having to get one for each.

Economics and the need to "Plug n Play" on the production line, drives standardisation

a modern wideband sensor is a 3 or 4 wire unit 1 signal 2 heater and on the 4 wire job the 4th is earth for the signal partner wire

Dave