P0137 keeps coming on. -checked for exhaust leaks and found none. -replaced downstream o2 sensor. -cleaned all fuel injectors and sprays nicely. -lastly, i thought it was wiring issue, so i bought whole wiring harness from ebay and replaced the entire wiring harness. But p0137 still comes on after a day of driving. Can anyone help?
That's a low voltage in the oxygen sensor circuit Why in the world would you change a whole wiring harness for that seems kind of odd when you could just trace down the wiring that goes to the O2 sensor what's it four wires heating sensing etc usually it's the heater that messes up in the O2 sensor which I think causes similar to a wiring issue because the heater is resistive And when it fails voltage stops or something along those lines and it's seen as a wiring or voltage problem so maybe you need to revisit that a little bit did you replace the oxygen sensor by chance?
Hello, someone suggested that it could be the wires, so i just decided to replace the whole wiring system. I went ahead and replaced the downstream o2 sensor with toyota denso sensor. The car's heater works fine and blows nice and hot. How do i check for heater issue?
The oxygen sensor has four wires connected to it. Two are for sensing oxygen, and two are to power an electric heater that is built into the sensor to keep it at the right temperature for sensing oxygen. The two places you get the most useful information for troubleshooting a problem with it are in the repair manual (in the troubleshooting section for P0137) and in the wiring diagram where it shows the connections to the sensor and which wires are which. Toyota Service Information and Where To Find It | PriusChat
If i replaced the o2 sensor with a brand new oem sensor, would it still be the issue with the heater in the o2 sensor? I am really lost here.
No by right it shouldn't be but maybe you have a faulty out of the box O2 sensor or a fake or something I have no idea We can't see from here but some things obviously going on because you still have the code with your replaced sensor right ??
The sensor's heater is built into the sensor, but the wires that bring the power to it are not. When the ECM gives you a trouble code about the sensor heater, it doesn't know where the cause of the trouble is. The ECM is stuck in a box bolted down under the hood, not like it can poke around and investigate. The human has to do that part.
