Denso 234-4172 Oxygen Sensor

OE-style oxygen sensor replacement

This Denso oxygen sensor is a specific-fit, heated replacement built to OE standards for accurate exhaust monitoring. It uses a threaded mounting design and a 4-wire female connector for a direct replacement on supported Mercedes-Benz applications.

Fits 1996-2003 Mercedes-Benz models in upstream and downstream positions, including ML55 AMG, SL600, ML320, ML430, CL500, CL600, S420, S500, S600, SL500, SLK230, C280, C36 AMG, E420, and SL320. Part number 234-4172 is listed for multiple OE-style applications across these vehicles.

Key features

• Heated oxygen sensor for faster operating response.
• Specific-fit design for exact replacement applications.
• Threaded mounting type for OE-style installation.
• 4-wire female connector with 10.43 in. harness length.
• Denso OE Style line with an aluminum oxide trap layer for element protection.

Detailed description

Denso 234-4172 is an OE-style oxygen sensor engineered for precise replacement on supported Mercedes-Benz vehicles. The sensor is manufactured and tested to OE standards, and its specific-fit construction helps ensure the correct connector, thread size, and harness layout for the application. The heated design supports quicker sensor operation, while Denso’s aluminum oxide trap layer helps protect the ceramic element from silicone and lead contamination.

This part cross-references Bosch (e.g., 13782, 15005) for the same application. If you are replacing a Mercedes-Benz oxygen sensor on an ML, SL, S-Class, or related platform, 234-4172 provides a direct-fit option that matches the listed OE-style requirements.

What it is used for

• Replacing a failed oxygen sensor that triggers engine management faults.
• Restoring accurate exhaust feedback for fuel control.
• Addressing poor fuel economy caused by an aging sensor.
• Correcting drivability issues related to slow or inaccurate sensor response.
• Resolving contamination-related sensor degradation.

Installation notes and tips

Verify the vehicle position and notes against the fitment list before ordering. Confirm the threaded mounting style, 4-wire connector, and harness length match the original sensor. On Mercedes-Benz applications, use the listed upstream or downstream position exactly as shown for the model and year.

Quality assurance

Denso manufactures this oxygen sensor to strict OE standards and tests it for exact replacement fitment. The OE Style line is built to deliver the correct part and fit for the listed applications.