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.
Most common after treatment systems will have two NOx sensors: One “upstream” on the turbo side of your Particulate Filter (DPF) and the second “downstream,” on the outlet side of your Catalyst (DOC). The two signals, sent directly to your Engine Control Module, are then compared to determine the “conversion efficiency” of your exhaust system.
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.