The veracity lies in the reference voltage, or the ability of the zirconium
dioxide and the platinum to react with oxygen.

The better the range of reaction the better the fuel control.

The full voltage range of the reaction will always be constant with the
elements themselves no matter who makes it.

So the variables are;    Temperature
                                           The purity of the elements
                                            The amount of resistance in the
reference
                                            voltage circuit.
                                             And of course the amount of
oxygen
                                            in the exhaust stream
Test controls;

Are the resistance wire's on your sensors the same length?

Boy for a minute there I thought would never get to the point!