NTK 25581 Oxygen Sensor

NTK Direct Fit Oxygen Sensor 25581

NTK Direct Fit Oxygen Sensor 25581 is a heated, specific-fit oxygen sensor built for direct replacement in select Porsche, Saab, and Volvo applications. It is designed with a 4-wire layout, 18 mm thread diameter, threaded mounting, and a 29.25 in. wiring harness length for OE-style serviceability.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for direct replacement applications
• 4-wire configuration with threaded mounting
• 29.25 in. wiring harness length
• 18 mm thread diameter
• Built by NTK, the Sensor Specialist and a major OE oxygen sensor supplier

Product Details

NTK 25581 is part of the Direct Fit Oxygen Sensor line, which focuses on OE-style fit, form, and function for import and domestic vehicles. NTK manufactures oxygen sensors using controlled ceramic technology and extensive production testing to help ensure consistent performance that meets or exceeds OE specifications. This sensor is a direct replacement choice for drivers servicing emissions and air/fuel monitoring systems on vehicles such as the Porsche 911, Saab 9-5, and Volvo 850.

This part cross-references Bosch 13577 and DENSO Auto Parts 234-4182 for the same application.

Vehicle Fitment

• Fits 1996-1997 Porsche 911, Upstream Right
• Fits 1999-2001 Porsche 911, Upstream Right
• Fits 1996-1997 Porsche 911, Upstream Left
• Fits 1999-2001 Porsche 911, Upstream Left
• Fits 1995-2001 Porsche 911, Downstream Right
• Fits 1995-2001 Porsche 911, Downstream Left
• Fits 1999 Saab 9-3, Upstream
• Fits 1999 Saab 9-3, Downstream
• Fits 1999 Saab 9-5, Upstream Right
• Fits 1999 Saab 9-5, Upstream Left
• Fits 1999 Saab 9-5, Upstream
• Fits 1999 Saab 9-5, Downstream
• Fits 1996-1998 Saab 900, Downstream
• Fits 1998 Volvo C70, Upstream
• Fits 1998 Volvo S70, Upstream
• Fits 1998 Volvo V70, Upstream
• Fits 1994-1997 Volvo 850, Upstream
• Fits 1995 Volvo 850, Upstream

Installation Notes

Verify the sensor position, connector style, and harness routing before installation. This NTK oxygen sensor uses a threaded mounting design and a 4-wire heated configuration, so matching the original sensor location and OE-style connector layout is important for proper fitment on Porsche 911, Saab 9-5, and Volvo 850 applications. Confirm the thread diameter and harness length against the removed sensor before service.

Quality Assurance

NTK is the world’s largest supplier and manufacturer of original equipment oxygen sensors. Each sensor is extensively tested during manufacturing to support quality and reliability aligned with OE specifications.