NTK 25684 Air / Fuel Ratio Sensor - Upstream
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NTK
 Direct Fit 4-Wire A/F Sensor

NTK 25684 Air / Fuel Ratio Sensor - Upstream

Brand NTK 25684
Position Upstream
Wiring Harness Length 15.8
Sensor Type Heated
Thread Length 0.38
Universal Or Specific Fit Specific
Wire Quantity 4
Thread Diameter 18.000
Mounting Bracket Included No
Product line Direct Fit 4-Wire A/F Sensor
Fits Suzuki · 8 vehicles

Direct-fit design. Built for specific application coverage and OE-style replacement.

Heated 4-wire sensor. Supports faster response and stable signal delivery.

OE-focused engineering. NTK tests sensors during manufacturing for quality and reliability.

Cross-references Bosch 18059, DENSO Auto Parts 234-9033 and DENSO Auto Parts 234-9299 for the same application. See all 6.

$196.03Free shipping
In stock · usually ships same day before 1pm CST
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Step 2 — Quantity
Order total $196.03
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Free returns within 60 days if it doesn't fit when fitment is verified.
Not what you need? See all Air / Fuel Ratio Sensor options

Direct-Fit Air/Fuel Sensor

NTK 25684 is a specific-fit, heated air/fuel ratio sensor built for OE-style replacement on select Suzuki applications. It uses a 4-wire design and is engineered for accurate upstream exhaust monitoring.

  • Specific-fit replacement for direct application coverage
  • Heated sensor design for faster operating response
  • 4-wire configuration for stable signal delivery
  • 18 mm thread diameter with 0.38 thread length
  • 15.8 wiring harness length for application-specific routing

Fitment Details

Compatible with select Suzuki models. Fits 2009-2013 Suzuki Grand Vitara, upstream. Fits 2007-2009 Suzuki SX4, upstream. This part cross-references Bosch 18059 and DENSO Auto Parts 234-9033 for the same application.

Product Overview

NTK 25684 belongs to the Direct Fit 4-Wire A/F Sensor line, which focuses on application-specific coverage and OE-style form. NTK is part of the NGK family of products and is known for oxygen sensor manufacturing with ceramic-based technology and extensive production testing. The result is a sensor line built to match original equipment expectations for fit, function, and signal performance. NTK 25684 is a practical choice when replacing a worn air/fuel ratio sensor on Suzuki Grand Vitara and Suzuki SX4 vehicles.

Common Replacement Issues

  • Check engine light related to air/fuel ratio sensor performance
  • Slow sensor response during closed-loop fuel control
  • Incorrect upstream exhaust feedback to the engine management system
  • Sensor aging that affects emissions monitoring and drivability

Installation Notes

Verify the connector style, thread size, and upstream application before installation. This sensor uses a heated 4-wire configuration and a specific-fit design, so matching the original routing and sensor location is important. Confirm the vehicle application against the part number 25684 and the listed fitment before replacement.

Quality Assurance

NTK tests these sensors during manufacturing to support quality and reliability that meet or exceed OE specifications. The part number 25684 is backed by NTK's OE-focused sensor engineering and application coverage.

Related reading

This part fits 8 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelLitersCylindersPositionNotes
2013SuzukiGrand Vitara2.4LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2012SuzukiGrand Vitara2.4LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2011SuzukiGrand Vitara2.4LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2010SuzukiGrand Vitara2.4LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2009SuzukiGrand Vitara2.4LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2009SuzukiSX42.0LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2008SuzukiSX42.0LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
2007SuzukiSX42.0LL4UpstreamOE design oxygen sensor fits Bank 1 Sensor 1 for air/fuel ratio.; Direct Fit 4-Wire A/F Sensor
Directly replaces or cross-references 6 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Bosch — 18059DENSO Auto Parts — 234-9033DENSO Auto Parts — 234-9299234-42991821378K001821380J00