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2001 Toyota Camry Rear Oxygen Sensors Keeps Failing

Hello. I drive a 2001 Toyota Camry with about 110,000 miles. About a year ago the check engine light came on and indicated a problem with the rear O2 sensor (the exact OBD code escapes me right now). Had the sensor replaced and a month later the same one failed. Replaced it again and 2 weeks later it failed again. I am now on the fourth rear O2 sensor and the check engine light is on again with the same code. So, clearly the problem isn’t the actual sensor. I have heard it might be the ECU, but what else could be causing this type of problem? Your responses are greatly appreciated!!

There are no codes that tell you a sensor is bad. So it’s often the case that people get codes, the codes reference some sensor’s circuit, so they replace the sensor, and then the same code comes back.

There are many, many codes and quite a few of those might have someone telling you that you need to replace an O2 sensor. So you’re going to need to get the specific code (format: P1234) and post it.

Most likely there is a wiring problem to the sensor. The code error will show that if it is the trouble by stating there is a problem with the sensor circuit. Sensors can also be damaged if coolant is leaking into the engine cylinders.

If the code translates to “Converter efficiency below threshold” then perhaps that is actually the problem…

Your Cat is likely and simply worn out…that’s why that sensor is there…nothing else. Ttime to pony up some dough.