NTK 25683 Oxygen Sensor - Upstream

Direct Fit Oxygen Sensor for OE Applications

NTK 25683 is a direct fit heated oxygen sensor built for specific vehicle applications and OE-style replacement needs. It is engineered for upstream air/fuel ratio monitoring on select Hyundai and Kia models, including Hyundai Elantra, Kia Soul, and Hyundai Tiburon.

As part of the NTK Direct Fit Oxygen Sensor line, this sensor focuses on correct fit, form, and function for import and domestic coverage. NTK uses ceramic manufacturing expertise and extensive production testing to help ensure the sensor meets or exceeds OE specifications.

Key Features

• Direct fit, specific application oxygen sensor
• Heated sensor design for faster operating readiness
• 4-wire configuration
• Threaded mounting type with 18 mm thread diameter
• 20.75 in. wiring harness length
• Upstream position for Bank 1 Sensor 1 air/fuel ratio monitoring
• OE-style replacement for select Hyundai and Kia applications

Vehicle Fitment

• Fits 2009-2012 Hyundai Elantra, upstream
• Fits 2010-2011 Kia Soul, upstream
• Fits 2007-2008 Hyundai Tiburon, upstream

Detailed Description

NTK 25683 is a direct fit oxygen sensor for vehicles that require an upstream heated sensor with a threaded mount and 4-wire design. It is listed for Hyundai Elantra, Kia Soul, and Hyundai Tiburon applications where Bank 1 Sensor 1 air/fuel ratio feedback is required. If you are replacing an upstream oxygen sensor on a 2009-2012 Hyundai Elantra, 2010-2011 Kia Soul, or 2007-2008 Hyundai Tiburon, this part number provides the OE-style configuration needed for proper installation and signal response.

NTK is known for oxygen sensor manufacturing and OE application coverage. Part number 25683 is built to support accurate exhaust monitoring and consistent sensor performance in the specified applications. This part cross-references Bosch 15644 and DENSO Auto Parts 234-4858 for the same application.

What This Sensor Helps Address

• Check engine light related to oxygen sensor circuit faults
• Incorrect air/fuel ratio feedback from the upstream sensor
• Slow sensor response during closed-loop operation
• Emissions test failures tied to oxygen sensor performance
• Rough fuel control caused by a worn Bank 1 Sensor 1 unit

Installation Notes and Quality Assurance

Verify the connector, wire count, thread size, and upstream location before installation. This NTK direct fit oxygen sensor uses a specific-fit design, so matching the vehicle application and sensor position is important for proper installation. Confirm the harness routing and mounting point against the original sensor before replacement.

NTK manufactures oxygen sensors with production testing intended to meet OE-level requirements for fit and reliability. The brand’s OE-focused sensor expertise and ceramic manufacturing background support consistent application coverage for part number 25683.