NTK 25723 Oxygen Sensor - Downstream Right or Upstream

Direct-Fit Oxygen Sensor

The NTK 25723 is a specific-fit heated oxygen sensor built for direct replacement applications. It uses a threaded mounting design and a 4-wire configuration to match the original sensor layout for covered vehicles, including Volkswagen R32 and Audi TT Quattro applications.

• Heated oxygen sensor for faster operating response.
• Specific-fit design for direct replacement use.
• Threaded mounting with 18 mm thread diameter.
• 13.75-inch wiring harness length for proper routing.
• 4-wire sensor configuration.

Fitment and Application Details

Fits 2004 Volkswagen R32, downstream right. Fits 2000-2002 Audi TT Quattro, upstream. This part cross-references Bosch (e.g., 16034, 16392) for the same application.

NTK’s Direct Fit Oxygen Sensor line is built to streamline replacement selection while maintaining OE-style fit, form, and function. As part of the NGK family and a major original equipment oxygen sensor supplier, NTK applies ceramic manufacturing expertise and manufacturing controls from raw material through finished sensor production. The NTK 25723 is tested during manufacturing to meet or exceed OE specifications for quality and reliability.

What It Helps Address

• Fault codes related to oxygen sensor performance.
• Incorrect air-fuel ratio feedback.
• Slow sensor response during closed-loop operation.
• Emissions issues tied to a worn or failed sensor.
• Driveability problems caused by inaccurate exhaust gas readings.

Installation Notes and Tips

Confirm the sensor position, thread size, wire count, and harness length before installation. This direct-fit sensor is intended to match the original connector and mounting style on listed applications, which helps reduce adaptation during replacement.

Quality Assurance

NTK tests these oxygen sensors during manufacturing to support OE-level quality and reliability. The brand’s OE-supplier background and ceramic sensor expertise are central to the design and production of the 25723.