The signal is already effectively digital as it only gives a high and a low voltage.

If its high then the ecu adjusts the mixture one way. If its low it adjusts the mixture the other way. When its reached its optimum the sensor is flicking from high to low.

The ecu doesn't know how rich or him lean the mixture is, just that it is rich or lean.

 

It's effectively a dynamic feedback loop.

There's little point in aiming for a constant stochio, since load and TPS and temp will be constantly changing accprding to driving conditions.

 

The ECU will need to be different for zirconia (0.2v-0.8v) to titania (0.01v-4.5v).

Apart from the voltage levels per se, titania sensors provide a step on/off signal transition rather than a continuously varying level, as I read it. In which case the ECU will need to interpret things rather differently. Mark?

 

Correct Mr Rog.

0-5v sensors are commonly called "Wideband" and can't be interpreted by the ecu, unless it was designed to. So we couldn't put one on the S for example.

I had one on my first S, but it was a clever one which also gave a normal 0-1v (narrowband) output to keep the ECU happy, but I could get the 0-5v Wideband readings in the car to get a good idea of the AFR

 

Some very useful info...thanks chaps