Delphi ES20418 Oxygen Sensor - Front Right, Rear, Rear Left or Rear Right

Delphi ES20418 Oxygen Sensor Overview

The Delphi ES20418 is a heated oxygen sensor built for precise exhaust monitoring in select BMW and Mercedes-Benz applications. With OE-based engineering and a 4-wire design, it supports accurate air-fuel feedback for rear and front-right positions where specified by the vehicle application.

Compatible With BMW 535i, BMW 535i xDrive, BMW 535xi, BMW 740i, BMW 740Li, BMW X6, Mercedes-Benz C240, C320, CLK320, CLK430, CLK55 AMG, and SLK55 AMG applications listed below.

• Heated oxygen sensor for faster operating temperature and stable signal output
• 4-wire configuration with round connector shape
• Thread size: 18 x 1.5 mm
• Overall length: 775.0
• Package contents: oxygen sensor and instruction sheet
• OE-focused design backed by Delphi’s long history supplying original equipment to major automakers

Detailed Product Description

Delphi ES20418 is an emission control oxygen sensor engineered for direct replacement in select BMW and Mercedes-Benz vehicles. It is listed for rear, rear right, rear left, and front right positions depending on the application, including rear manifold-mounted BMW 535i and 535i xDrive coverage, rear sensor use on BMW X6 and 740i/740Li models, and front-right or rear-left placement on select Mercedes-Benz CLK and C-Class vehicles. The heated sensor design helps the unit reach operating temperature quickly so the engine management system can read exhaust oxygen content sooner after startup. Delphi’s OE heritage and aftermarket experience are built into the part’s construction and calibration approach.

This part cross-references Bosch 16030 and DENSO Auto Parts 234-4876 for the same application. Part number ES20418 is also referenced in interchange listings for several OE and aftermarket numbers.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a failing upstream or downstream sensor
• Rough idle or drivability issues tied to exhaust feedback errors
• Reduced fuel economy caused by inaccurate sensor data
• Emission test failures linked to sensor response problems

Installation Notes and Tips

Verify the exact sensor position before ordering, since ES20418 is used in multiple locations including rear, rear right, rear left, and front right depending on the vehicle. Confirm the 18 x 1.5 mm thread size, 4-wire layout, round connector shape, and harness length requirements against the original part. For BMW 535i and 535i xDrive rear manifold applications, note the listed manifold location and model-year-specific harness lengths. Always compare the connector and routing to the original sensor before installation.

Quality Assurance

Delphi builds this oxygen sensor using OE experience gained from supplying major automakers for decades. The ES20418 is designed to meet the demands of modern emission control systems in BMW and Mercedes-Benz applications, with the sensor type, connector style, and fitment details aligned to the listed vehicle positions.