NTK 25199 Oxygen Sensor - Downstream

Direct Fit Downstream Oxygen Sensor

NTK 25199 is a direct fit heated oxygen sensor for downstream applications on select Hyundai and Kia vehicles. It is built with a specific-fit design, a 4-wire configuration, and a threaded mounting style for OE-style replacement on the listed applications.

As part of NTK’s Direct Fit Oxygen Sensor line, this sensor is engineered for import and domestic coverage with application-specific fitment. NTK uses ceramic manufacturing expertise and OE application knowledge to deliver fit, form, and function that align with original equipment requirements.

Key Features

• Heated oxygen sensor for downstream placement
• Specific-fit design for direct replacement
• 4-wire configuration
• 23.25 in. wiring harness length
• 18 mm thread diameter
• Threaded mounting type
• OE-style replacement for select Hyundai and Kia applications

Vehicle Fitment

• Fits 2011-2016 Kia Optima, Downstream
• Fits 2013-2015 Hyundai Santa Fe Sport, Downstream
• Fits 2011-2015 Hyundai Sonata, Downstream
• Fits 2014-2015 Hyundai Tucson, Downstream
• Fits 2011-2015 Kia Sorento, Downstream
• Fits 2014-2015 Kia Sportage, Downstream
• Fits 2010-2014 Hyundai Genesis Coupe, Downstream
• Fits 2009-2014 Hyundai Sonata, Downstream
• Fits 2010-2013 Hyundai Tucson, Downstream
• Fits 2010-2013 Kia Forte, Downstream
• Fits 2010-2013 Kia Forte Koup, Downstream
• Fits 2012-2013 Kia Forte5, Downstream
• Fits 2011-2013 Kia Optima, Downstream
• Fits 2011-2013 Kia Sportage, Downstream
• Fits 2010-2012 Hyundai Santa Fe, Downstream
• Fits 2009-2012 Kia Rondo, Downstream

Detailed Description

NTK 25199 is a downstream heated oxygen sensor for Hyundai Sonata, Kia Optima, and other listed Hyundai and Kia models. It is a direct fit replacement for B1S2 applications, including California emissions listings where noted, and is intended to match the original sensor location and connector-style requirements on the covered vehicles. This part cross-references Bosch 18043 and DENSO Auto Parts 234-4238 for the same application.

NTK is the sensor specialist within the NGK family of products and is a major OE oxygen sensor supplier. The brand’s manufacturing process controls the ceramic element from raw material through finished sensor, and each oxygen sensor is tested during production to help meet or exceed OE specifications.

Common Replacement Uses

• Check engine light related to downstream oxygen sensor performance
• Fault codes tied to air-fuel ratio monitoring after the catalytic converter
• Failed emissions inspection caused by sensor output issues
• Rough fuel control from an aging or contaminated sensor
• Replacement for damaged wiring or connector wear on the original sensor

Installation Notes

Confirm the vehicle year, engine/emissions configuration, and sensor position before ordering. This NTK 25199 sensor is specific fit and threaded, so the existing mounting point and harness routing should match the listed application. Use the fitment notes to verify B1S2 downstream coverage for your Hyundai or Kia model.

Quality Assurance

NTK manufactures oxygen sensors with OE-focused testing and application coverage to support reliable replacement performance. The brand’s direct fit line is built to deliver OE-style fit, form, and function for the listed Hyundai and Kia applications.