One of the common mistakes made in troubleshooting based on diagnostic codes is replacing the indicated sensor before performing basic circuit troubleshooting.

Codes do NOT indicate bad sensors. They DO indicate bad circuits of which sensors are almost always a key part. That is why the code is named for the sensor.

If every diagnostic code that is read were properly analyzed before buying the corresponding sensor, it would probably cut Auto Zone and the other auto supply stores gross sales by 10%. This is why Auto Zone is so anxious to draw codes for free because they will almost always sell a sensor whether it is needed or not.

Good luck.