Bosch 15246 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor for Lexus GS300

Bosch Validated Oxygen Sensor 15246 is a specific-fit, narrow-band heated O2 sensor built for precise air-fuel-ratio feedback to the ECU. It is compatible with 1998-1999 Lexus GS300 downstream applications for cylinder(s) 4, 5, and 6, making it a direct replacement for the original sensor on the listed vehicle.

Key Features

• Specific-fit oxygen sensor for confirmed Lexus GS300 downstream coverage
• Narrow-band heated design for stable closed-loop fuel control
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• 4-wire configuration with blade terminals and rectangular connector
• Wiring harness included for a cleaner replacement installation
• Metal housing and high-temperature-resistant construction for demanding exhaust conditions
• Bosch Validated Oxygen Sensor line backed by Bosch OE development experience

Detailed Description

Bosch part number 15246 uses a switching-type narrow-band design to report exhaust oxygen content to the engine control unit, helping maintain accurate fuel delivery and steady combustion control. Bosch developed this sensor line from its long-running OE oxygen sensor technology, including later planar narrowband designs that improve light-off speed, lambda accuracy, and closed-loop response. For Lexus GS300 owners servicing downstream sensor faults, Bosch 15246 provides the correct fitment and sensor architecture for the listed 1998-1999 applications.

This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough idle or unstable combustion control caused by aging sensor output
• Emissions test failures tied to oxygen sensor degradation
• Slow sensor response from heat cycling and exhaust exposure

Installation Notes and Tips

Fits 1998-1999 Lexus GS300, downstream. Confirm the connector shape, 4-wire layout, and threaded mounting style before installation. Use the 18 mm hex size for removal and installation, and verify the sensor location matches the downstream position for cylinder(s) 4, 5, and 6. Inspect the harness routing and connector condition during replacement to avoid strain on the new sensor lead.

Quality Assurance

Bosch has more than five decades of OE oxygen sensor development behind this Validated Oxygen Sensor line. The 15246 is built with ceramic sensing elements, controlled heater operation, and durable materials selected for high-heat exhaust environments.