I replaced my O2 sensor about 3 months ago or so after my new cat was installed. I had been getting a code 13 for it for a while and figured it was no good. I replaced it and I'm still getting the same code. I checked for open wires and nothing. I did have to repair some wires that found their way onto the exhuast manifold...part of the main harness that runs the fuel injectors, but i don't know if the O2 wire runs through there. The only thing I thought of was doesn't the sensor use the bung where it screws into as a ground. Maybe its not getting a good ground there. I'm not sure though. Anyone with some knowledge of this, I'd appreciated the help. Thank you.

 

Try backprobing the computer side of the O2 sensor connector and watching the voltage. Code 13 means that there is no O2 activity at all. This is usually caused by an open wire somewhere, so you might want to check again.

If you can backprobe with a Digital multimeter, the voltage should be 0.450V when the car is cold. The ECM feeds out a reference signal for diagnostic purposes when the car is cold, then once the O@ heats up, it start to create it's own voltages based on O2 content in the exhaust and the computer stops sending it the reference voltage.

 

What he said...and make sure there's no corrosion on the connectors anywhere. Electrical parts cleaner works real well for that.

 

sounds good...i haven't gotten around to it yet...but i'm replacing the front end today...so the car will be up in the air and everything accesible...so the reading should be at the above mentioned limit...i'll check for corosion on the terminal conector from the car becasue the sensor is brand new...i'll pull that loom off and follow the wire and see whats up...i'll be back with results later this afternoon and possibly lookin for some more help

 

No, the reading should be about 0.450 voltsd when the car is open loop(cold) and then should start swinging between 0.150V and 0.950V one it warms up. If you show that you have 0.450V all the time, then you need to check out the rest of the circuit before you just replace the sensor. the sensor might be bad and causing this, but it's better to check out the rest of it before you just go replacing parts.

 

Don't forget to clear the codes after you fix something. (Stupid, I know, but important.)