Check Engine Light Code P0031

good evening.

what kind of sensor did you use? it is a special sensor called an air fuel ratio sensor. if a standard sensor is used, it will not work.

Roy

Yes, I replaced it with the air fuel ratio sensor. I bought it from a Toyota parts store with part number 89467-06030. It is the oem sensor, so I do not understand why the code will not go away. I cleared it many times, but the check engine light and the same code will pop back up within a minute.

Are there any wiring issues to the sensor? There are many things that could cause the problem. For example, a bad connection, poor ground, bank 1 sensor 1 circuit fuse, or even a bad ECM. What you need to do is get your hands on a real time scanner which will allow you to watch how the sensor is reacting. That way you will know if there is even a signal from it. Please keep in mind, this is a heated sensor. The code indicates the heater component is experiencing low voltage. To me, that sounds like a connection problem or damaged wiring. Take a look at the pic I found.