Genuine Mercedes Secondary Air Injection Pump Hose

Genuine Mercedes Secondary Air Injection Pump Hoses

When a Mercedes-Benz engine starts cold, its secondary air injection system briefly pushes fresh air into the exhaust stream so the catalytic converters reach operating temperature quickly and unburned hydrocarbons are oxidized. The secondary air injection pump hose is the link that carries that air between the pump, the shut-off or combi valve, and the exhaust side of the engine. A Genuine Mercedes hose is the same factory-specification component the vehicle was built with, which matters in a system where routing, fit, and heat tolerance are all tightly defined.

Why Factory-Spec Matters for This Hose

These hoses live in a demanding environment. They sit close to the exhaust manifolds and cylinder heads, so they see engine-bay heat, vibration, and exposure to moisture and condensation. Mercedes-Benz designs each hose and air pipe around a specific engine layout, so molded bends, connector ends, and lengths are matched to particular applications rather than being a generic universal fit. Genuine parts are engineered to work with the surrounding components, which helps avoid the leaks, loose connections, and stray air that can cause trouble in the emissions system.

Applications Across Mercedes-Benz Engine Families

Mercedes-Benz catalogs these parts under several names, including molded hose, air pipe, shut-off valve tube, and connector hose, so it helps to search by part number as well as description. Part numbers span a wide range of engine generations, from older V8 and V12 applications to the later M272 V6 and M156 6.3L V8 engines. Examples of the types of parts in this category include:

• Intake-side hoses that feed air to the secondary air pump on M272 V6 and related V8 engines
• Connector hoses that link the pump to the shut-off valve on 1990s through 2000s sedans, coupes, and SUVs
• Left and right side air pipes that route air toward each cylinder bank on AMG V8 applications
• Hoses for earlier models such as the 400E, 500E, and 500SL, which use their own dedicated part numbers

Because many part numbers have been superseded over the years, a current Genuine Mercedes hose may replace an earlier number for the same position. Confirming the position (left or right), engine, and model year before ordering is the surest way to get the correct hose.

When to Replace These Hoses

Rubber and molded plastic hoses harden and crack with age and repeated heat cycles. Common signs of a failing hose include a check-engine light with secondary air system fault codes, a hissing or unusual noise at cold start, or visible cracking at the connector ends. Replacing the hose is often a sensible step alongside diagnosing a pump or valve fault, since a leaking line can mimic a failing component. Installing a genuine replacement restores the original sealing and fit so the system can pass its self-checks as designed.

Explore More

For a wider look at how these parts work and the other brands that make them, visit the full Secondary Air Injection Pump Hose category. To see everything else the manufacturer offers, head to the Genuine Mercedes brand page.