Delphi ES20366 Oxygen Sensor - Rear

Delphi ES20366 Rear Oxygen Sensor

Delphi ES20366 is a heated rear oxygen sensor built for precise exhaust monitoring on select Saturn Ion models. It combines OE-based engineering with a 4-wire design, square connector, and 18 x 1.5 mm thread size for a direct-fit replacement on the rear position.

Compatible with 2003-2004 Saturn Ion rear applications, this Delphi oxygen sensor supports accurate feedback to the engine management system. The ES20366 is also a fitment-based search match for 2003 Saturn Ion rear oxygen sensor and 2004 Saturn Ion rear oxygen sensor replacement needs.

Key Features

• Heated oxygen sensor for faster operating temperature
• Rear position application
• 4-wire configuration
• Square connector shape
• 18 x 1.5 mm thread size
• Overall length: 940.0
• Includes oxygen sensor and instruction sheet
• Delphi part number ES20366

OE-Based Design

Delphi draws on more than a century of OE experience and supplier knowledge used by major automakers. That background is reflected in the ES20366, which is engineered as an aftermarket oxygen sensor replacement with OE-style fit and function for the rear exhaust location on Saturn Ion models.

This part cross-references Bosch 15044 for the same application.

What It Helps Address

• Check engine light related to rear oxygen sensor performance
• Incorrect exhaust oxygen feedback to the engine control system
• Reduced fuel control accuracy from a worn sensor
• Emissions test failures tied to sensor response issues
• Driveability concerns caused by aging exhaust monitoring components

Installation Notes

Verify the rear sensor location, connector shape, and thread size before installation. Compare the original sensor length and wire configuration to the Delphi ES20366, and follow the included instruction sheet during replacement. Confirm the vehicle is a 2003-2004 Saturn Ion rear application before ordering.

Quality Assurance

Delphi builds aftermarket parts using OE heritage and application knowledge developed through long-term supplier experience with leading automakers. The ES20366 is produced to support dependable fitment and consistent sensor operation in the specified Saturn Ion rear applications.