NOx sensor fault

The word lambda normally refers to the o2 sensor which could be before or after the catalytic converter.

The NOx sensor is normally referred to as the upstream sensor because it is check the engines ability to burn the fuel properly. Also, it is giving a base line to see if the converter is reducing the emissions properly which is the difference in NOx from the upstream and downstream.

So unfortunately these terms are all to general be give you a specific answer that the code you are looking at and the part you are looking at are the same component.

If you provide the code, we can possibly get you the part number for what would be needed.

Good evening,

I attached the location of the sensor for you. The NOX sensor measures the amount of NOX not burned up in the combustion chamber. When it is too high, it will code warning you that it needs attention.

https://www.2carpros.com/articles/how-an-oxygen-sensor-works

Roy