NTK 25674 Air / Fuel Ratio Sensor - Upstream
OE Quality 60-Day Returns
NTK
 Direct Fit 4-Wire A/F Sensor

NTK 25674 Air / Fuel Ratio Sensor - Upstream

Brand NTK 25674
Position Upstream
Wiring Harness Length 24.5
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 Mazda · 1 vehicle

Direct-fit design. Specific application replacement for straightforward emission control service.

Heated sensor. Built for faster operating response and stable signal performance.

OE-spec testing. Manufactured and tested to meet or exceed OE specifications.

Cross-references Bosch 18119, DENSO Auto Parts 234-9086 and L362188G1 for the same application. See all 3.

$195.46Free shipping
In stock · usually ships same day before 1pm CST
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Step 2 — Quantity
Order total $195.46
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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 ratio sensor

NTK 25674 is a direct-fit, specific application air/fuel ratio sensor for emission control service. It is a heated 4-wire sensor with OE-equivalent design details for accurate replacement on the listed application.

  • Specific-fit sensor for direct replacement service
  • Heated design for faster operating response
  • 4-wire configuration for the listed application
  • 18 mm thread diameter with 0.38 thread length
  • 24.5 in. wiring harness length

Application details

Fits 2005 Mazda 6, upstream. The fitment notes identify this as the front sensor, located in the manifold, with B1S1 and California emissions coverage. For Mazda 6 emission control repair, NTK 25674 matches the specified direct-fit 4-wire air/fuel ratio sensor application.

This part cross-references Bosch 18119 and DENSO Auto Parts 234-9086 for the same application.

What it helps correct

  • Faulty air/fuel ratio sensor readings
  • Check engine light concerns tied to sensor performance
  • Emission control drivability issues from an aging sensor
  • Incorrect mixture feedback to the engine control system

Installation notes and quality

Use the fitment notes to confirm upstream placement, manifold location, and California emissions coverage before installation. The sensor is listed as a specific-fit, direct-fit replacement, and the mounting bracket is not included.

NTK is part of the NGK family and is a major original equipment oxygen sensor supplier. NTK 25674 is manufactured and tested to meet or exceed OE specifications for fit, form, and function.

Related reading

This part fits 1 vehicle
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelTransmissionLitersCylindersPositionNotes
2005Mazda6Automatic2.3LL4UpstreamFront Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor
Directly replaces or cross-references 3 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Bosch — 18119DENSO Auto Parts — 234-9086L362188G1