A NOx sensor is a device that measures the amount of nitrogen oxides (NOx) in the exhaust of a diesel engine. NOx is a pollutant that can contribute to smog and acid rain. The NOx sensor helps to control the amount of NOx that is emitted from the engine, which helps to improve air quality.
There are two types of NOx sensors: upstream and downstream. The upstream NOx sensor is located before the catalytic converter, and the downstream NOx sensor is located after the catalytic converter. The upstream NOx sensor measures the amount of NOx in the exhaust before it is treated by the catalytic converter. The downstream NOx sensor measures the amount of NOx in the exhaust after it has been treated by the catalytic converter.
The NOx sensor is a critical part of the diesel emissions control system. If the NOx sensor fails, the engine may not be able to pass emissions testing. The NOx sensor can also cause other problems, such as decreased fuel economy and increased emissions.
If you have a diesel vehicle, it is important to have the NOx sensor checked regularly. The NOx sensor should be replaced every 50,000 to 100,000 miles, depending on the manufacturer’s recommendations.
Here is a list of error codes for different vehicles that may be related to a NOx sensor:
- P0496 – NOx sensor circuit low voltage
- P0497 – NOx sensor circuit high voltage
- P0498 – NOx sensor heater circuit low voltage
- P0499 – NOx sensor heater circuit high voltage
- P2002 – NOx sensor 1 upstream bank 1
- P2003 – NOx sensor 1 downstream bank 1
- P2004 – NOx sensor 2 upstream bank 2
- P2005 – NOx sensor 2 downstream bank 2
If you see one of these error codes on your vehicle’s dashboard, it is important to have the NOx sensor checked by a qualified technician.