Audi A8 D4 Lambda Probe Oxygen Sensor Cylinder 5-8 4.2 TDI CDSB 4H0906262C

Audi A8 D4 Lambda Probe Oxygen Sensor Cylinder 5-8 4.2 TDI CDSB is a precision oxygen sensor from the Lambda probes and O2 sensors group, designed specifically for the 4.2 TDI diesel engine. It enables stable control of the mixture composition, supports the proper operation of the injection system, and reduces exhaust emissions, which translates into efficient engine and exhaust system performance.

Specifications and technical data

• SKU: 4H0906262C
• Mark: Audi
• Condition: Used
• OEM Part Number: 4H0906262C
• Substitutable numbers: 4H0906262C, 4H0 906 262 C
• Category: Oxygen Sensors

Application and function in the 4.2 TDI CDSB engine

The described lambda probe operates in the cylinder 5–8 area of the 4.2 TDI CDSB engine, transmitting information about the oxygen content in the exhaust gases to the engine control unit. This allows the controller to continuously adjust the fuel dose, injection timing, and turbocharging strategy.

A functional oxygen sensor in this location is crucial for:

• maintaining the correct air-fuel mixture within the engine's operating range,
• stable idling and performance under load,
• reducing smoke and excessive emissions of nitrogen oxides and particulate matter,
• protecting exhaust system components, including catalytic converters and filters.

Benefits of using an original Audi lambda probe

The component comes from the original Audi parts line, which means full compatibility with the factory engine controller characteristics and ECU software. In practice, this translates into:

• correct signal interpretation by the controller without the need for non-factory map adaptation,
• stable operating parameters across the entire temperature range,
• preservation of factory engine and exhaust system protection strategies.

For high-displacement diesel units such as the 4.2 TDI, using the correct oxygen sensor has a direct impact on engine refinement, fuel consumption, and component durability.

Condition, verification, and selection by part numbers

The offered lambda probe is a used component, which allows for cost-effective repair while maintaining the manufacturer's original specifications. Before being offered for sale, such components are standardly verified for the integrity of the housing, wiring, connector, and the absence of mechanical damage that could affect signal readings.

The selection of a lambda probe for the Audi A8 D4 with a 4.2 TDI CDSB engine should always be based on catalog numbers and data from the manufacturer's system. In practice, this means checking compatibility by the OEM part number and any interchangeable numbers to ensure proper cooperation with the specific version of the engine controller.

To better understand the principles of selecting and installing used sensors and control modules, it is worth reading the Global Parts guide: used automotive electronics and sensors – a practical guide to selection and installation.

Importance for diagnostics and exhaust system operation

In the case of the Audi A8 D4 with a 4.2 TDI CDSB engine, a faulty lambda probe in the cylinder 5–8 area can cause a number of symptoms, such as:

• increased fuel consumption and loss of dynamics,
• appearance of errors in the engine controller related to fuel corrections,
• irregular idling,
• accelerated wear of exhaust cleaning components.

Replacing it with a functional, original oxygen sensor restores correct exhaust composition readings, facilitates diagnostics, and allows for reliable data interpretation from diagnostic testers. This is particularly important for advanced V8 TDI units, where several lambda probes work in parallel with an extensive control system.

System expansion – other Audi lambda probes and O2 sensors

If you are planning a comprehensive repair or upgrade of your Audi's engine area and need other components from the same group, such as additional pre-catalyst probes, post-catalyst probes, or O2 sensors in other sections of the exhaust system, check the available parts in the Audi Lambda probes and O2 sensors category.

When deciding whether to choose an original part, a replacement, or a used part, the Global Parts guide may also be helpful: original, replacement, and used parts – a comparison of costs and profitability.