NTK 25139 Oxygen Sensor - Upstream

Direct Fit Oxygen Sensor

NTK 25139 is a direct-fit oxygen sensor built for specific import applications and engineered for accurate exhaust monitoring. It uses a threaded mounting design, a non-heated sensing element, and a 19-inch wiring harness for the specified fitment.

Key Features

• Direct-fit oxygen sensor for specific applications
• Non-heated sensor design
• Threaded mounting type
• 19-inch wiring harness length
• Single-wire configuration
• OE-equivalent design for proper fit and function

Detailed Description

NTK 25139 is part of the Direct Fit Oxygen Sensor line, created to streamline application coverage while maintaining OE-style fit, form, and function. NTK draws on its ceramics expertise and original equipment manufacturing background to produce oxygen sensors that are extensively tested during manufacturing for quality and reliability. This part cross-references Bosch 12040 for the same application. Compatible with Volkswagen Golf and Volkswagen Jetta applications listed below, NTK 25139 supports the upstream oxygen sensor location specified in the fitment data.

What It Is Used For

• Replacing a worn or slow-responding oxygen sensor
• Restoring accurate exhaust oxygen signal output
• Addressing sensor-related drivability or emissions faults
• Correcting fitment issues caused by an incorrect sensor style
• Supporting emissions system diagnostics on the listed applications

Installation Notes and Tips

Verify the connector style, thread diameter, and harness length before installation. This sensor is a specific-fit replacement, so match the vehicle application and upstream position exactly to the catalog listing. Use the fitment notes to confirm the 2-pin connector and OE-equivalent design requirements for the vehicle.

Quality Assurance

NTK states that its oxygen sensors are tested during manufacturing to meet or exceed OE specifications. As part of the NGK family of products and a major original equipment oxygen sensor supplier, NTK focuses on fit, form, and function consistency across its application coverage.