i installed a 3wire heated o2 sensor.

and i also installed a digital 02 gauge with a bar graph that goes up n down reading between rich/lean

once the car has fully warmed up does the o2 sensor supposed to have a steady straight constant reading or is it supposed to constantly slightly bounce a few .volts all the time?


i only ask because my bar graph display is constantly jumping slowly between rich and lean mostly stays somewhere in the middle but not sure if its suppsoed to keep changing bars up n down so much


any one know how the o2 sends a signal to the ecm?

 

The jumping around indicates it's working normally. Every time the voltage crosses the .45volt point, it generates a o2 crosscount. The higher the cross counts, the better. The sensor generates a small amount of voltage. The richer the mixture is, the higher the voltage.