NTK 25670 Oxygen Sensor - Downstream or Intermediate

Direct Fit Oxygen Sensor for Mazda Applications

The NTK 25670 is a direct fit heated oxygen sensor built for specific Mazda applications, including downstream and intermediate locations. It uses a threaded mounting design with a 4-wire configuration and a 32.25-inch wiring harness for OE-style replacement on select Mazda 2, Mazda 3, Mazda 3 Sport, and Mazda 6 models.

Key Features

• Direct fit, specific application oxygen sensor
• Heated sensor design for faster operating response
• 4-wire configuration
• 32.25-inch wiring harness length
• 18 mm thread diameter with threaded mounting type
• OE-equivalent design for select downstream and intermediate positions

Product Details

NTK Direct Fit Oxygen Sensor 25670 is part of the brand’s OE-focused oxygen sensor line, developed with ceramic manufacturing expertise and extensive production testing. NTK supplies oxygen sensors for import and domestic vehicles and emphasizes fit, form, and function that align with original equipment requirements. This part cross-references Bosch 15914 and DENSO Auto Parts 234-4329 for the same application.

Compatible With select Mazda fitments, this sensor is used in downstream and intermediate exhaust positions on California-emissions vehicles where accurate exhaust feedback is required. It is a practical replacement choice for Mazda 3 oxygen sensor service, Mazda 3 Sport center sensor replacement, and Mazda 6 rear sensor applications.

What This Oxygen Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Fault codes tied to downstream or intermediate sensor readings
• Reduced exhaust monitoring accuracy after catalyst operation
• Rough idle or drivability issues caused by incorrect air-fuel feedback
• Emissions test failures linked to sensor response problems

Installation Notes and Tips

• Verify the sensor position before ordering: downstream or intermediate.
• Confirm the vehicle uses the listed threaded 18 mm mounting style.
• Check harness routing and connector reach against the 32.25-inch lead length.
• Use the vehicle’s exact year, model, and emissions configuration to confirm application.
• For Mazda 2, Mazda 3, Mazda 3 Sport, and Mazda 6 applications, match the OE sensor location shown in the fitment data.

Quality Assurance

NTK manufactures oxygen sensors with OE-level application coverage and tests them during production to support consistent performance and reliability. The brand’s direct fit oxygen sensor line is built to meet or exceed original equipment specifications for the listed Mazda applications.