NTK 25718 Oxygen Sensor

Direct Fit Oxygen Sensor for Hyundai and Kia

NTK 25718 is a direct fit heated oxygen sensor built for specific Hyundai and Kia applications. It is engineered for OE-style fit, form, and function, with coverage for upstream and downstream positions on select Genesis, Equus, K900, and Borrego models.

Key Features

• Heated oxygen sensor with a specific-fit design
• Threaded mounting type with 18 mm thread diameter
• 4-wire configuration for OE-style signal and heater circuit operation
• 15.75 in. wiring harness length
• Designed to meet or exceed OE specifications through manufacturing validation
• Direct fit replacement for select Hyundai Genesis, Hyundai Equus, Kia K900, and Kia Borrego applications

Product Details

NTK 25718 is part of the NTK Direct Fit Oxygen Sensor line, a product line focused on application-specific replacement sensors for import and domestic vehicles. NTK uses ceramic-based sensor technology and OE application coverage to deliver a replacement oxygen sensor that matches the original mounting and electrical layout. This part number is used across multiple positions, including upstream right, upstream left, downstream right, and downstream left, depending on the vehicle application. For buyers searching for an oxygen sensor for Hyundai Genesis or a Kia K900 oxygen sensor, NTK 25718 provides a direct-fit solution with OE-equivalent design intent.

This part cross-references DENSO Auto Parts (e.g., 234-4239, 234-4240) for the same application.

What This Oxygen Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings from a worn sensor
• Slow sensor response affecting fuel control
• Heater circuit faults on heated oxygen sensor applications
• Emissions test failures tied to sensor degradation

Installation Notes and Fitment

• Fits 2015-2017 Kia K900, Upstream Right
• Fits 2015-2017 Kia K900, Upstream Left
• Fits 2015-2017 Kia K900, Downstream Right
• Fits 2015-2017 Kia K900, Downstream Left
• Fits 2011-2016 Hyundai Equus, Upstream Right
• Fits 2011-2016 Hyundai Equus, Upstream Left
• Fits 2011-2016 Hyundai Equus, Downstream Right
• Fits 2011-2016 Hyundai Equus, Downstream Left
• Fits 2009-2016 Hyundai Genesis, Upstream Right
• Fits 2009-2016 Hyundai Genesis, Upstream Left
• Fits 2009-2016 Hyundai Genesis, Downstream Right
• Fits 2009-2016 Hyundai Genesis, Downstream Left
• Fits 2009-2011 Kia Borrego, Upstream Right
• Fits 2009-2011 Kia Borrego, Upstream Left
• Fits 2009-2011 Kia Borrego, Downstream Right
• Fits 2009-2011 Kia Borrego, Downstream Left

Confirm the sensor position before installation, since NTK 25718 is used in multiple upstream and downstream locations. Match the connector, thread size, and harness routing to the original sensor on the vehicle. For Hyundai Genesis and Kia Borrego oxygen sensor replacement, verify Bank and Sensor location against the removed part.

Quality Assurance

NTK is the sensor specialist within the NGK family of products and is a major original equipment oxygen sensor supplier. Each sensor is manufactured and tested to support OE-level fit and reliability for the listed Hyundai and Kia applications.