NOx sensors

NOx sensors measure the emission of nitrogen oxides (NOx) in the exhaust gas and send the data to the control unit in order to adjust the urea dosage in the SCR system. They help to monitor the efficiency of NOx conversion in the catalytic converter and optimize it in real time.

In modern exhaust systems, there are often two sensors, one before and one after the catalytic converter. These measure the nitrogen oxide emissions in order to determine the conversion efficiency. This mode of operation ensures that vehicles can comply with legally prescribed limit values for nitrogen oxides.

Technology and functionality

• 12 / 24 volt sensors
• Double chamber principle

Consequences of failure:

• Engine indicator light flashes (possibly exhaust gas purification light)
• Saving an error code
• Increased emissions – The consequence can be a failure to pass the emissions test
• Regeneration problems
• Power loss and increased fuel consumption

Causes for the failure:

• Missing connection to the control unit
• Internal short circuits
• Mechanical damage
• Overheating
• Ageing and wear

Advantages:

• OE quality
• Many sensors for common vehicle types
• For passenger cars and commercial vehicles (LDV/HD)