What Does A NOx Sensor Do?

Thu May 05 2022 Yan Xia

As engine emission regulations become more stringent than ever, the NOx (Nitrous Oxide) sensor’s role is to analyze the emissions and determine nitrogen oxide quantities released into the environment.


The NOx sensor works by detecting nitrogen oxides via an electro-catalytic mechanism, with a material that reacts with NOx.

A voltage passed through an electrolyte can assess how much NOx is present, with the more substantial voltage representing a more significant NOx level.

Suppose the NOx sensor detects that there are excessive quantities of NOx produced. In that case, it will transmit the information to the SCR system, which will then adjust the output to allow the vehicle to conform to emissions regulations.

For this reason, the NOx sensor is vital for the SCR system in diesel-powered cars to ensure that the vehicle continues to conform to the emissions standards required.

For those looking for an in-depth explanation, we highly recommend looking at this excellent video from ADPTraining.

What Does A NOx Sensor Do?