How do you convert the voltage from the o2 sensor to the Air/Fuel Ratio? Or is it to dificult to do?

 

A stock O2 sensor is sometimes called a "lambda sensor". A characteristic of this type of sensor is that its' output suddenly changes when the AF ratio is richer or leaner than the stoichiometric value. With the sensor in an LT1, I think that ~470mV represents stoich. Whatever the number is exactly, it will increase rapidly to a max of ~850-900mV when the mixture goes richer than 14.7:1 and quickly down to ~100mV when it's leaner. As a result, it can only be used to determine if the mixture is at stoich, richer, or leaner.

A wide band O2 sensor has a much more linear response to changes in AF ratio. Using one of these, you can determine AF ratio over a wide range. Each particular sensor design will have a different response curve and you need to have this calibration to use it. If you have the calibration, it's easy. Here is osme more information which may be useful. http://vehicle.me.berkeley.edu/~markw/efi/SAE920289/

Rich Krause