Voltage to O2 sensors

[Steves LX]

Does anyone know how much voltage should be going to the O2 sensors? I checked mine last night at the hego power pin at the connector next to the mass air and it was only .2 volts both with the car running and the key on engine off. I for some reason believe that should be 12 volts not .2 but would like some clarification on this if anyone knows.

[quik lx]

Hey Steve, the Ignition/Run circuit sends out 12VDC to both O2's and the Mass air. (check the dark green wire with the pink tracer for the right one/ Dark blue with a light green tracer for the left.) A lean condition will send a voltage of less than .4VDC back to the EEC on pin 29 for the right one and pin 43 for the left one. A return voltage of .6VDC or greater indicates a rich condition. The O2's produce voltage feedback of 0-1.1 volts. You should also have good ground on the other wire. Hope this helps. Joe

[Steves LX]

O.K. Joe I appreciate that. So tell me this am I checking the voltage in the right spot by checking it at the connector where the pig tail for the O2's hook up. The pin I checked was Hego power. Or do I need to check it back at the computer on bothe pin 43 nand 29 and if so do I do this with the car running or what. I want to get an accurate voltage reading and I dont want to screw nothing up.