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Delphi ES20188 Oxygen Sensor - Rear
| Brand | Delphi ES20188 |
|---|---|
| Position | Rear |
| Connector Shape | Square |
| Overall Length | 445.0 |
| Package Contents | Oxygen Sensor, Instruction Sheet |
| Sensor Type | Heated |
| Thread Size | 18 x 1.5 mm |
| Wire Quantity | 4 |
| Fits | Subaru · 16 vehicles |
Heated sensor. Provides faster operation for dependable emissions monitoring.
Square connector. Simplifies installation with a straightforward electrical connection.
OE heritage. Built on 100 years of OE experience and supplier knowledge.
Cross-references Bosch 15814, DENSO Auto Parts 234-4132 and Gates 24598 for the same application. See all 12.
Will it fit your vehicle?
Free return shipping if it doesn't fit.
Delphi ES20188 Rear Oxygen Sensor
Delphi ES20188 is a heated rear oxygen sensor built for precise exhaust monitoring on select Subaru applications. It uses a 4-wire design, a square connector, and an 18 x 1.5 mm thread size for direct replacement service on the listed vehicles.
Key Features
- Heated oxygen sensor for faster operating temperature
- 4-wire configuration with square connector shape
- 18 x 1.5 mm thread size
- Overall length: 445.0
- Rear position application
- Package contents: oxygen sensor and instruction sheet
Application Details
Compatible with rear oxygen sensor locations on 1999-2004 Subaru Legacy, 2000-2004 Subaru Outback, and 2003-2006 Subaru Baja. For 1999 Subaru Legacy, this part applies to rear positions without California Emission System equipment. Delphi ES20188 is also a direct-reference choice for shoppers searching Subaru Legacy rear oxygen sensor, Subaru Outback rear O2 sensor, or Subaru Baja rear oxygen sensor replacement.
Built from Delphi’s OE heritage and decades of supplier experience, this sensor reflects the same engineering focus used in original equipment development. The result is a replacement part intended to match the required sensor layout and electrical connection for the listed Subaru fitments. This part cross-references Bosch 15814 and DENSO Auto Parts 234-4132 for the same application.
What It Helps Address
- Check engine light related to rear oxygen sensor performance
- Incorrect exhaust feedback readings from a worn sensor
- Slow sensor response after extended mileage
- Fuel control issues caused by inaccurate exhaust data
- Failed emissions inspection tied to sensor malfunction
Installation Notes
Verify rear sensor placement, connector shape, wire count, and thread size before installation. Compare the original sensor length and connector style to the Delphi ES20188 before removal. Use proper exhaust sensor service practices to avoid damaging the threads or wiring during replacement.
Quality Assurance
Delphi builds this oxygen sensor using OE-focused engineering knowledge developed through long-term original equipment supply experience. That background supports consistent fitment, connector design, and sensor construction for the specified Subaru applications.
| Year | Make | Model | Transmission | Position | Notes |
|---|---|---|---|---|---|
| 2006 | Subaru | Baja | — | Rear | — |
| 2005 | Subaru | Baja | — | Rear | — |
| 2004 | Subaru | Baja | — | Rear | — |
| 2004 | Subaru | Legacy | — | Rear | — |
| 2004 | Subaru | Outback | — | Rear | — |
| 2003 | Subaru | Baja | — | Rear | — |
| 2003 | Subaru | Legacy | — | Rear | — |
| 2003 | Subaru | Outback | — | Rear | — |
| 2002 | Subaru | Legacy | — | Rear | — |
| 2002 | Subaru | Outback | — | Rear | — |
| 2001 | Subaru | Legacy | Automatic | Rear | — |
| 2001 | Subaru | Outback | Automatic | Rear | — |
| 2000 | Subaru | Legacy | Automatic | Rear | — |
| 2000 | Subaru | Outback | Automatic | Rear | — |
| 1999 | Subaru | Legacy | — | Rear | — |
| 1999 | Subaru | Legacy | — | Rear | without California Emission System |
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