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What is a NOx sensor?

The NOx Sensor is a sensor commonly mounted on the exhaust system before the catalytic converter that monitors the nitrogen oxide level being emitted by a diesel engine.

How long do NOx sensors last?

A NOx sensor can last between 50,000 to 60,000 miles. With proper maintenance, the sensor can last for more than that. In the same manner, it can fail long before covering 50k miles and need replacement. Nox sensor are very common on the new Mercedes with the Adblue system to have issues 


Does AdBlue affect NOx sensor?

If the NOx sensor goes on the blink, the car's SCR system doesn't know how much AdBlue to inject into the exhaust system. Rather than not injecting enough and possibly causing polluting exhaust gases to be emitted, it's likely to inject more than the car needs.

How to know if my NOx sensor has failed?

The NOx sensor would usually bring up the EML light and Adblue fluid will be low even after filling back up. 

If this happens then after the amount of miles on the Adblue display the car will not start even with a full tank of Adblue due to sensor not reading the correct amount.

What to do if your NOx sensor fails?

If you suspect your NOx sensor has failed bring the car to us so we can carry out a quick fault code diagnostics and we will let you know if it is the NOx sensor.

If it is the NOx sensor we trained mechanic to fix this problem don't wait as this may cause further issues.



Just call us on 01634239595

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