NTK 25726 Oxygen Sensor - Upstream

Direct Fit Oxygen Sensor

NTK 25726 is a direct fit oxygen sensor built for specific applications and engineered for accurate air/fuel ratio feedback. It uses a heated, threaded design with a 3-wire configuration and a 38.5-inch harness for a precise replacement on select Mercedes-Benz models.

Key Features

• Direct fit oxygen sensor for specific applications
• Heated sensor design for faster operating response
• Threaded mounting with 18 mm thread diameter
• 3-wire construction with 38.5-inch wiring harness
• OE-style fit, form, and function

Detailed Description

NTK 25726 is part of NTK’s Direct Fit Oxygen Sensor line, created to streamline replacement selection while maintaining OE application coverage. NTK is a major original equipment oxygen sensor supplier, and this sensor is manufactured with ceramic technology and tested during production to meet or exceed OE specifications. It is a direct replacement for select Mercedes-Benz 420SEL, 560SEC, 560SEL, and 380SEC applications, including upstream Bank 1 Sensor 1 positions where listed. This part cross-references DENSO Auto Parts 234-3081 and Delphi ES10260 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air/fuel ratio feedback
• Slow sensor response from a worn heated sensor
• Faulty upstream sensor readings on listed Mercedes-Benz applications

Installation Notes and Tips

Verify the threaded mounting style, 3-wire layout, and harness length before installation. Confirm the vehicle’s upstream sensor location and match the application notes for Bank 1 Sensor 1 where specified. Use the part number 25726 to confirm the correct direct fit replacement before ordering.

Quality Assurance

NTK manufactures oxygen sensors with OE-focused application coverage and production testing for reliability. Part number 25726 is built to meet or exceed OE specifications for the listed applications.