NTK 24659 Air / Fuel Ratio Sensor - Upstream

Direct-Fit Air/Fuel Ratio Sensor

NTK 24659 is a direct-fit, heated air/fuel ratio sensor built for specific import applications. It uses a 4-wire design and OE-style dimensions to support accurate exhaust feedback where precise mixture control matters.

Key Features

• Direct-fit replacement for specific applications
• Heated sensor design for faster operating response
• 4-wire configuration for the correct electrical interface
• 18 mm thread diameter with 0.38 thread length
• 31.0 wiring harness length for proper routing
• Mounting bracket not included

Detailed Description

NTK 24659 is engineered as a specific-fit air/fuel ratio sensor for the Saab 9-2X and Subaru Impreza in upstream Bank 1 Sensor 1 applications. As part of NTK's Direct Fit 4-Wire A/F Sensor line, it is built to match OE-style fit, form, and function for vehicles that rely on accurate air-fuel monitoring. The part number 24659 is also referenced in cross-application listings such as Bosch 15537 and DENSO Auto Parts 234-9011 for the same application.

NTK draws on its oxygen-sensor manufacturing background and ceramic technology to produce sensors that are extensively tested during manufacturing for quality and reliability. For buyers searching for a Subaru Impreza upstream air/fuel ratio sensor or a Saab 9-2X Bank 1 Sensor 1 replacement, NTK 24659 provides a direct-fit solution with the correct heated 4-wire setup.

What It Is Used For

• Replacing a failed upstream air/fuel ratio sensor
• Restoring accurate fuel mixture feedback to the engine control system
• Addressing sensor-related drivability or emissions faults
• Correcting wiring or connector mismatch from an incorrect sensor
• Servicing OE-style emissions control on Saab 9-2X and Subaru Impreza applications

Installation Notes and Tips

Verify the vehicle's year, make, model, and upstream Bank 1 Sensor 1 location before ordering. Confirm the 4-wire heated sensor configuration and compare the thread diameter, thread length, and harness length to the original part. The mounting bracket is not included, so reuse or source any required bracket separately if your application uses one.

Quality Assurance

NTK states that this sensor is extensively tested during manufacturing and built to meet or exceed OE specifications. NTK is part of the NGK family of products and is recognized as a major original equipment oxygen sensor supplier.