NTK 24520 Oxygen Sensor - Downstream or Upstream

Direct Fit Oxygen Sensor Overview

The NTK 24520 is a direct fit heated oxygen sensor built for specific Subaru applications. It uses a threaded mounting design and OE-style form, fit, and function to support accurate exhaust feedback in the correct application.

Key Features

• Heated oxygen sensor for faster operating response.
• Specific-fit design for direct application matching.
• Threaded mounting type for secure installation.
• 17.75-inch wiring harness length.
• 3-wire sensor configuration.
• 18 mm thread diameter.

Detailed Description

NTK 24520 is part of the Direct Fit Oxygen Sensor line, a product line focused on application-specific replacement sensors. NTK is known for oxygen sensor manufacturing and uses ceramic technology control from raw material through finished production. This sensor is engineered for Subaru Forester, Subaru Impreza, and Subaru Legacy applications listed below, with downstream coverage for 1998 Forester and 1995-1998 Impreza and Legacy, plus upstream coverage for 1995-1997 Impreza and 1995 Legacy. This part cross-references DENSO Auto Parts 234-3088 and Delphi ES10439 for the same application.

Common Issues This Part Can Address

• Faulty oxygen sensor signal output.
• Delayed sensor response after warm-up.
• Check engine light conditions related to oxygen sensor performance.
• Incorrect air-fuel feedback in the exhaust system.
• Replacement needs for a worn threaded sensor assembly.

Installation Notes and Quality

Verify the sensor position, thread size, wire count, and harness length before installation. Use the listed fitment to confirm whether the application is downstream or upstream for your Subaru Forester, Impreza, or Legacy. NTK states that these oxygen sensors are extensively tested during manufacturing to meet or exceed OE specifications.