Audi A4 B9 A5 F5 NOx Sensor 2.0 TDI Diesel 8W0907807BC

Audi A4 B9 A5 F5 NOx Sensor 2.0 TDI Diesel is an exhaust system component from the Lambda sensors and O2 sensors group, responsible for precise measurement of nitrogen oxides in diesel engines. Thanks to the use of a dedicated NOx sensor for 2.0 TDI units, it is possible to maintain stable engine operating parameters and ensure proper operation of exhaust gas treatment systems. This solution helps reduce the risk of ECU errors and ensures compliance with exhaust emission requirements.

Specifications and technical data

• SKU: 8W0907807BC
• Mark: Audi
• Condition: Used
• OEM Part Number: 8W0907807BC
• Substitutable numbers: 8W0907807BC, 8W0 907 807 BC
• Fuel type: Diesel
• Category: Oxygen Sensors

Purpose and function of the NOx sensor

The NOx sensor in Audi A4 B9 and A5 F5 diesel models is responsible for continuous monitoring of exhaust gas composition regarding nitrogen oxides. Based on its signal, the engine control unit (ECU) adjusts the fuel dose, injection system operation, and emission reduction strategy, which translates into stable engine performance and reduced wear of exhaust system components. In the event of a malfunctioning NOx sensor, errors may appear in the ECU memory, leading to power loss, limp mode activation, or increased fuel consumption. Replacing it with a functional unit from the same design group allows for the restoration of correct control logic and avoids costly secondary repairs.

Benefits of using an original Audi sensor

By using a NOx sensor from the Audi range, you gain:

• Full compatibility with the ECU software – the signal from the sensor is interpreted exactly as intended by the vehicle manufacturer.
• Stable operation of the diesel exhaust treatment system, without random errors or unforeseen system reactions.
• Reduced risk of OBD diagnostic issues and frequent warning lights on the instrument cluster.
• The ability to maintain factory emission parameters, which is important for technical inspections and exhaust gas tests. For diesel units, sensor reading repeatability is particularly important, as even minor deviations can lead to improper operation of the NOx reduction system and accelerated wear of exhaust system components.

Installation and operational characteristics

The presented NOx sensor is designed for diesel-powered engines used in the Audi A4 B9 generation and Audi A5 F5 generation. The sensor's construction has been developed for operation in high exhaust temperatures and environments with variable chemical composition, which requires appropriately selected materials and measurement electronics. In practice, installation involves replacing the existing sensor in the exhaust system with a unit of the same specification, while maintaining the correct tightening torque and proper routing of the signal cable. After installation, it is recommended to perform adaptation or clear errors using an appropriate diagnostic tester so that the engine control unit can correctly interpret the signal from the new component.

Why consider a used NOx sensor

In the case of engine electronics and measurement elements such as NOx sensors, choosing a used component allows for a significant reduction in repair costs while maintaining the original manufacturer's specification. A properly selected element from the same design family can operate in the vehicle just as stably as a new one, provided that correct diagnostics and installation are performed. If you want to better understand how to safely select and install used modules and sensors, check out our guide: Used automotive electronics on board – why is it worth choosing second-hand ECU modules and sensors?. There, you will find practical tips regarding selection by identification numbers, compatibility issues, and installation procedures.

Expanding Audi exhaust system support

If you are planning a comprehensive repair or upgrade of the exhaust system area in your Audi and need other elements from the same group, such as additional probes, oxygen sensors, or exhaust measurement components, check the available parts in the Audi Lambda sensors and O2 sensors category. This allows you to ensure a consistent technical condition of the entire exhaust measurement path in one service stage, which facilitates diagnostics, improves engine performance, and reduces the risk of the same faults returning in a short time.