Resolved Should O2 reading jump around?

[spoolinawd91]

the o2 reading should jump around a lot at idle when the car warms up right? Because mine doesn't move at all so I'm guessing my o2 sensor is dead?

 

[dnhieu]

your o2s should be cycling between .2 and .8. if they dont you are correct.

 

[steve]

On '91 ECU's once the coolant temps go over 86F the ECU goes closed loop and starts dithering the fuel to make the O2's cycle. ('90 ECUs wait until something like 126F)

If the sensor is working you'll see the voltage start climbing from startup as it warms up until the ECU enters closed loop and they cycle.

Steve