Delphi ES20223 Oxygen Sensor - Rear, Rear Left or Rear Right

Delphi ES20223 Oxygen Sensor Overview

The Delphi ES20223 is a heated oxygen sensor built for rear exhaust positions on select Subaru and Toyota applications. It uses a 4-wire design with a square connector and 18 x 1.5 mm thread size, making it a direct-fit replacement for vehicles that need accurate exhaust feedback after the catalytic converter.

Delphi draws on OE experience from supplying major automakers, and that heritage is reflected in the fit, connector design, and sensor construction of this replacement part.

Key Features

• Heated oxygen sensor for rear, rear left, and rear right positions
• 4-wire configuration for stable signal and heater circuit operation
• Square connector shape for application-specific fitment
• 18 x 1.5 mm thread size for threaded exhaust mounting
• Overall length of 340.0 for vehicle-specific routing
• Includes oxygen sensor and instruction sheet
• Delphi ES20223 cross-references Bosch 13355 for the same application

Detailed Description

The Delphi ES20223 oxygen sensor is engineered for rear exhaust monitoring on 2003-2004 Toyota 4Runner, 2005-2014 Subaru Outback, 2008-2014 Subaru Legacy, 2008-2014 Subaru Tribeca, and 2006-2007 Subaru B9 Tribeca applications. It is also a direct replacement for rear left and rear right positions on the 2003-2004 Toyota 4Runner. If you are searching for a rear oxygen sensor for Subaru Outback or a rear O2 sensor for Toyota 4Runner, this part number provides the fitment and connector style needed for those vehicles.

Built with Delphi OE heritage, the ES20223 is intended to restore proper exhaust gas monitoring after the catalytic converter. The heated design helps the sensor reach operating temperature quickly, while the 4-wire layout supports consistent signal performance in the exhaust stream. The square connector and threaded mounting help simplify replacement when the original sensor matches these specifications.

What This Oxygen Sensor Helps Address

• Check engine light related to rear oxygen sensor performance
• Fault codes tied to slow sensor response or heater circuit issues
• Incorrect exhaust feedback after the catalytic converter
• Emissions inspection failures caused by a worn rear O2 sensor
• Rough fuel control behavior linked to inaccurate exhaust readings

Installation Notes and Tips

Confirm the exact rear position for your vehicle before ordering, since this part fits rear, rear left, and rear right locations depending on application. Match the connector shape, wire count, and thread size to the original sensor before installation. For the correct Subaru Legacy, Subaru Outback, Subaru Tribeca, Subaru B9 Tribeca, or Toyota 4Runner application, refer to the vehicle fitment details and compare the original sensor routing and mounting location.

Quality Assurance

Delphi builds aftermarket parts using OE experience and knowledge developed through long-term supplier relationships with major automakers. That background supports the design and application accuracy of the ES20223 oxygen sensor.