Secondary O2 Sensor Help
 

Does anyone know what the CEL code P0141(65) "Secondary heated O2 sensor heater circuit fault" means?

Does this mean the sensor is bad or another part of the circuit is bad?

In my Haynes Manual there are a few problem codes listed with the O2 sensor such as "O2 circuit low voltage" , "O2 circuit high voltage", "O2 circuit slow response". I'm not sure which one means to change the O2 sensor.

Also, is there a problem in not replacing a bad secondary O2 sensor. I am having a problem with fluctuating idle where the car's idle will fluctuate so low that the car actually turned off. I know about the FITV and the IAC, but I'm wondering if a bad secondary O2 sensor can cause this also.

Will I fail emissions if the sensor is bad?

Thanks in advance.

You will most likely fail emissions if your o2 sensor is bad.
Bad idle could also mean your dizzy is about to go.
I know for my car, when I turned on the car, the car would just seem to idle very low, then shut off. The problem was with the dizzy.

My car was and is still pulling a P0420 Code.
I've changed the Cat, and both o2 sensors but the damn code won't go away -_-

Your teg will fail emissions with a bad O2 sensor.

In regards to your idle problem, the O2 sensor should have little to do with it; when the sensor's temperature drops to a certain point (it has a set operating temperature, somewhere in the range of 500 degrees C), it will no longer feed the ECU information, and send it into open loop.

Essentially, the ECU will run off stored parameters when your idling. The secondary sensor is responsible for monitoring catalytic efficiency; if it can no longer operate properly, then your ECU will no longer be capable of emission control.

According to your initial post, it says circuit fault? so id assume its a circuit problem. Check the wiring and see if its been freyed or whatnot. Slap a new O2 in cause a new one is always better than a used one. Might not be needed, but still better.

Check the wires.

IMO

The code means pretty much what it says.

The O2 sensor has a built in heater element because they don't work well when cold. That code means that the heater element has busted. The sensor may still function properly as its heated up by the exhaust anyway. A quick look at the live data with a scan tool would tell you that.

Basically you are screwed though, you are going to have to replace the sensor to get rid of the CEL.