Audi A8 D4 Adblue Tank Reservoir Bottle 4H0131873A

Audi A8 D4 Adblue Tank Reservoir Bottle is an original AdBlue additive supply system component, belonging to the Fuel tanks and filler pipes group. Designed by the vehicle manufacturer, it ensures the proper operation of the exhaust emission reduction system in the Audi A8 D4 generation. This used OEM component is a sensible choice for drivers who want to maintain the factory design of the system and stable operating parameters.

Specifications and technical data

• SKU: 4H0131873A
• Mark: Audi
• Condition: Used
• OEM Part Number: 4H0131873A
• Substitutable numbers: 4H0131873A, 4H0 131 873 A
• Category: Fuel Tanks & Filler Necks

Purpose and function in the AdBlue system

The presented AdBlue tank is responsible for the safe storage of the urea solution and its delivery to the exhaust system, which enables effective reduction of nitrogen oxide emissions. As an element from the Fuel tanks and filler pipes group, it works with other components of the supply system, ensuring tightness, proper fluid circulation, and correct operation of the SCR system in the Audi A8 D4.

Thanks to its factory design and fitment for the specific model, the tank maintains the correct geometry of mounts and connections, which translates into stable seating in the body and proper cooperation with the vehicle's installation.

Original origin and fitment for Audi

As an Audi brand product, the AdBlue tank was developed in accordance with the vehicle manufacturer's internal standards. This means maintaining factory dimensional tolerances, compatibility with original wiring harnesses, hoses, and brackets, as well as predictable behavior during long-term operation. An original element from this group minimizes the risk of assembly problems, leaks, or diagnostic system errors related to the improper operation of the AdBlue system.

Choosing such a component is particularly important for modern engines, where the emission reduction system is closely integrated with the engine control electronics. Factory fitment limits the need for modifications and allows for compliance with the design assumptions of the Audi A8 D4.

Condition, verification, and service application

The item is offered as used, which allows for a significant reduction in repair costs compared to a new OEM subassembly, while maintaining the original design. This type of tank will work well both for a standard replacement of a damaged element and for broader service work related to the AdBlue additive supply system, e.g., after a collision or corrosion of the mounts.

Due to the specific nature of the SCR system's operation, using an original tank helps maintain correct fluid dosing parameters, which affects stable engine operation, the absence of errors in the controller, and compliance with emission standards. It is a practical solution for workshops specializing in the Audi brand and users who expect a predictable repair result.

Integration with the fuel system and diagnostics

Although the AdBlue tank is not a classic fuel tank, in service practice, it is treated as part of the vehicle's broader supply system. Its condition has a direct impact on the correct operation of the exhaust gas cleaning system, and thus on the results of computer diagnostics and any warning messages on the dashboard. When replacing, it is worth paying attention to the tightness of the connections, the condition of the hoses, and the proper venting of the system.

For users and mechanics who want to deepen their knowledge about the operation of the entire supply system, a guide describing the construction and maintenance of key elements, such as injectors, pumps, and tanks, will be useful. A detailed discussion can be found in the article Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration, where practical diagnostic and operational tips are presented.

Selection support and system expansion

When selecting an AdBlue tank for the Audi A8 D4, it is crucial to rely on the vehicle manufacturer's data and part markings, which helps avoid compatibility problems. In case of doubt, it is worth verifying compliance using catalog numbers or service documentation to ensure that the installed element will work with the existing installation.

If you are planning a comprehensive repair or upgrade of the supply and fluid storage area in your Audi and need other elements from the same group, such as filler hoses, additional tanks, or mounting elements, check the available parts in the Audi fuel tanks and filler pipes category.

For those who think long-term about the value of their car, understanding the impact of original used components on the vehicle's resale price may also be important. This topic is discussed more broadly in the guide Original used parts vs. car resale price – how not to lose money?, showing why choosing branded elements is beneficial not only technically but also economically.