Bosch 15313 Oxygen Sensor - Upstream

Bosch Validated Oxygen Sensor for Lexus GS300

Bosch Part Number 15313 is a specific-fit, narrow-band heated oxygen sensor built for precise air-fuel ratio feedback to the ECU. It is listed for the 1998-1999 Lexus GS300 upstream position on cylinders 4, 5, and 6, making it a direct-match option for emissions and drivability service.

Key Features

• Specific-fit oxygen sensor for confirmed Lexus GS300 applications
• Upstream narrow-band heated O2 sensor design
• 4-wire configuration with blade terminals and rectangular connector
• Threaded mounting with 18 mm thread size and 22 mm hex size
• Wiring harness included with 17.1 in harness length
• Standard replacement grade for emission control service
• Bosch Validated Oxygen Sensor line backed by OE development experience

Product Details

Bosch 15313 uses a switching-type sensing element to report oxygen content in the exhaust stream so the engine control unit can maintain stable closed-loop fuel control. The heated narrow-band design helps the sensor reach operating temperature faster and maintain consistent signal response under changing load and temperature conditions. For Lexus GS300 owners, this part number 15313 is a direct service solution for the upstream sensor location specified for 1998-1999 models.

The Bosch Validated Oxygen Sensor line focuses on OE-style fit, durable construction, and accurate signal output. Bosch has decades of oxygen sensor development behind its aftermarket coverage, including ceramic sensing elements, controlled heater operation, and materials selected for high heat and vibration exposure. This makes Bosch 15313 a practical choice when replacing a worn upstream sensor on a Lexus GS300.

This part cross-references 8946530440 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Rich or lean fuel trim conditions caused by slow sensor response
• Reduced closed-loop fuel control accuracy
• Failed emissions inspection tied to upstream O2 sensor faults
• Rough idle or drivability issues linked to incorrect air-fuel feedback

Installation Notes

Fits 1998-1999 Lexus GS300, upstream. Confirm the connector shape, 4-wire layout, and threaded mounting style before installation. Use the correct oxygen sensor socket for the 18 mm hex, and inspect the exhaust bung threads for damage or contamination before threading in the new sensor. Verify the harness routing keeps the lead away from exhaust heat and moving components.

Quality Assurance

Bosch draws on more than five decades of OE oxygen sensor development, and the Validated Oxygen Sensor line is built to deliver OE-proven fit and signal performance for aftermarket replacement.