The NOx sensor (Nox) is used to detect nitrogen oxides in exhaust gases. NOx is the collective name for nitrogen oxides NO and NO2, which appear under the influence of high pressure and temperature during the combustion of the fuel mixture in the engine. Another name for the sensor is a nitrogen oxide sensor or a lean mixture sensor.
The NOx sensor is part of the exhaust gas aftertreatment system. Such sensors began to equip cars to meet the requirements of environmental standards Euro 5 and higher.
The exhaust aftertreatment system in engines also uses AdBlue, which is also called “urea”, and a catalytic converter. The composition of AdBlue is about 33% urea and the rest is demineralized water.
Malfunction of the NOx sensor;
NOx sensors are clogged;
Malfunction of the SCR catalyst;
Connectors and wires corrode (due to leaks of corrosive urea liquid);
Failure of urea heating elements in the AdBlue tank;
Failure of the AdBlue pump;
Faulty AdBlue injector.
Lack of maintenance leads to the replacement of almost all elements of the system, which ultimately leads to huge costs.
It is easier and cheaper to disable the NOx and AdBlue sensor, forget about the problems and continue to enjoy the car.