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OE Quality
60-Day Returns
NTK 25669 Air / Fuel Ratio Sensor - Upstream
NTK Direct Fit Air/Fuel Ratio Sensor
NTK 25669 is a direct fit, heated 4-wire air/fuel ratio sensor for specific Mazda applications. It is built for upstream, front sensor placement in the manifold and supports California emissions-equipped vehicles with OE-equivalent design.
Key Features
- Direct fit replacement for specific Mazda 3 and Mazda 3 Sport applications
- Heated sensor design for faster operating temperature
- 4-wire configuration for factory-style electrical connection
- 18.0 in. wiring harness length
- 18.000 mm thread diameter with 0.38 in. thread length
- Specific fit application for upstream, front sensor location
- No mounting bracket included
Product Details
NTK is the Sensor Specialist and a major original equipment oxygen sensor manufacturer, with ceramic-based sensor production and manufacturing controls that support consistent fit, form, and function. Part number 25669 is engineered as an OE-equivalent direct fit air/fuel ratio sensor for 2004-2009 Mazda 3 and 2009 Mazda 3 Sport models in the upstream position. This part cross-references DENSO Auto Parts 234-9085 for the same application.
Common Issues This Sensor Can Address
- Check engine light related to air/fuel ratio sensor performance
- Rough idle caused by inaccurate upstream sensor readings
- Fuel trim concerns from a slow or failing front sensor
- Emissions test failure tied to sensor response or signal quality
- Driveability issues on Mazda 3 and Mazda 3 Sport models with California emissions
Installation Notes
Verify the upstream, front sensor location before ordering. This NTK 25669 sensor is specific fit and uses a factory-style 4-wire connection, so matching the connector and thread specifications is important. Confirm manifold mounting, thread diameter, and harness length against the original sensor on the vehicle.
Quality Assurance
NTK manufactures oxygen and air/fuel ratio sensors with extensive testing during production to help ensure quality and reliability that meet or exceed OE specifications. The brand’s OE application focus and ceramic sensor expertise support consistent replacement performance for Mazda 3 and Mazda 3 Sport applications.
| Brand | NTK |
|---|---|
| Part Number | 25669 |
| Position | Direct Fit 4-Wire A/F Sensor, Upstream |
| Wiring Harness Length | 18.0 |
| Sensor Type | Heated |
| Thread Length | 0.38 |
| Universal Or Specific Fit | Specific |
| Wire Quantity | 4 |
| Thread Diameter | 18.000 |
| Mounting Bracket Included | No |
This part fits 11 vehicles. Search below:
| Year | Make | Model | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|
| 2009 | Mazda | 3 | 2.3L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2009 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2009 | Mazda | 3 Sport | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2008 | Mazda | 3 | 2.3L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2008 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2007 | Mazda | 3 | 2.3L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2007 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2006 | Mazda | 3 | 2.3L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2006 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2005 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
| 2004 | Mazda | 3 | 2.0L | L4 | Upstream | Front Sensor; Located in Manifold; B1S1; Calif. Emissions; OE Equivalent Design; Direct Fit 4-Wire A/F Sensor |
* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
This part directly replaces or is cross-referenced with the following part numbers:
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.