Mercedes-Benz S-Class W221 Air Filter Box Housing Left N/S A6420903301

The Mercedes W221 Left Air Filter Housing is a factory original intake system component, designed for installation on the left side of the engine bay in W221 S-Class models. This used, original housing ensures proper air flow to the filter, stable filter element mounting, and compatibility with factory brackets and hoses. It's a practical solution for users looking to restore correct intake function without investing in new parts.

Specifications and technical data

• SKU: A6420903301
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420903301
• Substitutable numbers: A6420903301, A 642 090 33 01
• Location on the vehicle: Left
• Category: Air Filter Housings

Purpose and Function in the Intake System

The left-side air filter housing in the Mercedes W221 is responsible for the stable seating of the filter element and the airtight routing of air drawn into the engine. A correctly selected component from this group allows for:

• maintaining the appropriate airflow to the powertrain,
• preserving the intake system's seal to factory standards,
• limiting the ingress of contaminants before the filter,
• ensuring correct mounting of hoses and sensors cooperating with the intake.

By using an original housing from the same series, the intake system retains the parameters specified by the manufacturer, which promotes stable engine operation and facilitates potential future servicing.

Compatibility and Left-Side Vehicle Installation

The presented housing is specifically designed for installation on the left side of the vehicle, which is important for both intake geometry and component placement within the engine bay. Proper matching of shape and mounting points translates to:

• easier installation in factory locations without modifications,
• correct routing of air hoses and any fastening clamps,
• maintaining clearance relative to other components in the engine bay.

Choosing a dedicated, left-side air filter housing for the W221 minimizes the risk of stress, leaks, and improper hose positioning, which is crucial for long-term operation.

Characteristics of a Used OEM Part

The air filter housing comes from the original Mercedes production line, meaning it retains factory dimensional tolerances and compatibility with other intake components. As a used part, it offers an economical alternative to new components while maintaining:

• compliance with factory brackets and mounts,
• appropriate structural rigidity of the housing,
• the possibility of further use after correct installation.

For many owners of older W221 S-Class models, using a used air filter housing is a sensible compromise between cost and maintaining the original intake system specification.

Why Choose Original Mercedes Air Filter Housings

In premium vehicles like the Mercedes W221, the intake system is designed with great attention to detail, so using a factory air filter housing helps maintain:

• structural consistency of the entire intake,
• easy service access to the filter element,
• predictable engine behavior under various load conditions.

If you need other components from the Air Filter Housings group intended for this brand's vehicles, check the available parts in the Mercedes Air Filter Housings category.

Practical Operational Tips and Additional Materials

When replacing the air filter housing, it's worth paying attention to the condition of the intake hoses, clamps, and the filter element itself to restore the full functionality of the air intake system in one go. Caring for these elements not only affects engine running smoothness but also the aesthetics of the engine bay and the overall condition of the vehicle.

If you are interested in a broader approach to maintaining the exterior elements of your car in good condition, including wheels and other visible components, a guide on the refurbishment and purchase of alloy wheels might be helpful: Used Wheels Like New: A Guide to Buying and Refurbishing Alloy Wheels.