/live/media/DE/DE_ES20371_Fro.jpg)
Will it fit your vehicle?
Confirm before you buy. Free return shipping if it doesn't fit.
Delphi ES20371 Oxygen Sensor - Rear
| Brand | Delphi ES20371 |
|---|---|
| Position | Rear |
| Connector Shape | Square |
| Overall Length | 830.0 |
| Package Contents | Oxygen Sensor, Instruction Sheet |
| Sensor Type | Heated |
| Thread Size | 18 x 1.5 mm |
| Wire Quantity | 4 |
| Fits | Mazda · 4 vehicles |
Heated sensor. Delivers faster operation for more consistent emissions monitoring.
Square connector. Simplifies hookup with a straightforward electrical connection.
OE heritage. Built with 100 years of OE experience and supplier knowledge.
Cross-references Bosch 15914, Bosch 15922 and DENSO Auto Parts 234-4390 for the same application. See all 24.
Will it fit your vehicle?
Free return shipping if it doesn't fit.
Rear Heated Oxygen Sensor for Mazda 3 and 5
Delphi ES20371 is a rear heated oxygen sensor built for specific Mazda applications that require accurate exhaust feedback after the catalytic converter. It uses a 4-wire design with a square connector and 18 x 1.5 mm thread size for direct replacement service.
Built from Delphi’s OE heritage and supplier experience, this oxygen sensor reflects the engineering knowledge used in aftermarket replacement parts. It is a strong match for drivers searching for a rear oxygen sensor for 2004-2005 Mazda 3 without California Emission System or 2006-2007 Mazda 5 rear applications.
- Heated oxygen sensor for rear position service
- 4-wire configuration with square connector
- Thread size: 18 x 1.5 mm
- Overall length: 830.0
- Includes oxygen sensor and instruction sheet
- Delphi ES20371 replacement part number
Application Details
This Delphi oxygen sensor is engineered for rear placement on 2004-2005 Mazda 3 models without California Emission System and 2006-2007 Mazda 5 models. If you are searching for a rear oxygen sensor for Mazda 3 or Mazda 5, Delphi ES20371 provides the correct fitment profile for those listed vehicles.
This part cross-references Bosch 15914 and DENSO Auto Parts 234-4390 for the same application.
Common Replacement Reasons
- Check engine light related to oxygen sensor performance
- Slow or inaccurate exhaust oxygen readings
- Rear sensor fault codes after catalytic converter monitoring issues
- Rough emissions test results tied to sensor response
- Need for a direct-fit rear oxygen sensor replacement on Mazda 3 or Mazda 5
Installation Notes
Confirm rear sensor placement, connector shape, and thread size before installation. Compare the existing harness routing and overall length to the original unit, and verify the vehicle is the non-California Emission System version where required. Follow the included instruction sheet and use proper exhaust sensor removal practices to avoid thread damage.
Quality Assurance
Delphi builds aftermarket parts using OE experience and knowledge developed through long-term supply relationships with major automakers. ES20371 is designed to meet the fitment and connection requirements of the listed Mazda applications.
| Year | Make | Model | Position | Notes |
|---|---|---|---|---|
| 2007 | Mazda | 5 | Rear | — |
| 2006 | Mazda | 5 | Rear | — |
| 2005 | Mazda | 3 | Rear | without California Emission System |
| 2004 | Mazda | 3 | Rear | without California Emission System |
| No rows match your filter. | ||||