Once the NOx sensor detects the amount of Nitrogen Oxide reaches the set value, the control circuit of NOx sensor will transmit signals to the engine ECU, and then the engine ECU will signal the Urea injector to inject Urea solution to the emission system. Injected Urea solution will have chemical reaction under high temperature, and then reduce the emission of those harmful gas, and reach the standards of Automobile Exhaust Gas Regulations.

Two very significant features of NOx sensors:
1) NOx...  more