NTK 25505 Oxygen Sensor - Upstream

Direct-Fit Oxygen Sensor for BMW Applications

NTK oxygen sensor 25505 is a direct-fit, threaded heated sensor built for specific applications. It uses a 3-wire design with a 21.2500-inch harness and an 18.000 thread diameter for a precise replacement on compatible BMW air/fuel ratio systems.

Key Features

• Direct-fit oxygen sensor for specific applications
• Heated sensor design for faster operating response
• 3-wire configuration with 21.2500-inch wiring harness
• Threaded mounting style with 18.000 thread diameter
• NTK 25505 is backed by OE-focused sensor engineering

Detailed Description

NTK 25505 is part of the Direct Fit Oxygen Sensor line, which focuses on application-specific replacement sensors rather than universal designs. NTK builds oxygen sensors with ceramic expertise and OE-level manufacturing control, and this part is extensively tested during production to meet or exceed original equipment specifications. It is a strong match for BMW 325, BMW 325e, BMW 325es, BMW 535i, BMW 635CSi, and BMW 735i upstream applications where a threaded heated oxygen sensor is required. This part cross-references DENSO Auto Parts 234-3016 for the same application.

What This Part Helps Address

• Faulty oxygen sensor readings
• Delayed sensor response during warm-up
• Air/fuel mixture control issues
• Check engine light concerns related to sensor performance
• Replacement needs for threaded upstream sensor locations

Installation Notes and Tips

Verify the connector style, thread size, and harness length before installation. Confirm the upstream location and application details against the vehicle service information for BMW 325, BMW 325e, BMW 325es, BMW 535i, BMW 635CSi, and BMW 735i. Use the part number 25505 to confirm the correct direct-fit replacement before ordering or installation.

Quality Assurance

NTK states that its oxygen sensors are manufactured and tested to meet or exceed OE specifications. As part of the NGK family of products, NTK focuses on OE application coverage and production consistency for import and domestic sensor applications.