Bosch 15238 Oxygen Sensor - Downstream

Bosch Engineered Oxygen Sensor 15238

Bosch Oxygen Sensor 15238 is a direct-fit, heated narrow-band O2 sensor built for downstream exhaust monitoring. It delivers precise air-fuel-ratio feedback to the ECU, helping maintain stable combustion control and lower emissions in supported Chevrolet, GMC, Buick, and Cadillac applications.

The Bosch Engineered Oxygen Sensor line draws on Bosch OE development dating back to the original oxygen sensor design and later planar narrowband technology. That engineering focus supports faster light-off, accurate lambda measurement, and quicker closed-loop operation under demanding heat and vibration conditions.

Key Features

• Direct-fit oxygen sensor for specific vehicle applications
• Heated narrow-band design for faster sensor response
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• 4-wire configuration with blade terminals and included wiring harness
• Oblong male connector for OE-style electrical connection
• Metal housing with high-temperature-resistant construction
• Overall length: 12 in; sealing surface to connector end: 10.8 in
• Standard replacement grade for downstream exhaust monitoring

Detailed Description

Bosch 15238 is a threaded downstream oxygen sensor engineered for precise exhaust feedback in vehicles that rely on narrow-band sensor input for fuel control. It is a heated, direct-fit unit with a specific-fit harness, making it a practical replacement for OE-style service on applications such as the Chevrolet Camaro, Chevrolet Colorado, GMC Canyon, Buick LaCrosse, Cadillac ATS, Cadillac CTS, Cadillac CT6, and Chevrolet Corvette. This part number, 15238, is built to match the electrical and mechanical requirements of the original sensor location.

This Bosch Engineered Oxygen Sensor uses advanced ceramic sensing elements and optimized heater control to support consistent operation across a wide range of temperatures. Bosch 15238 is cross-referenced to 12665161 and 12683553 for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor performance
• Incorrect air-fuel feedback reaching the ECU
• Slow sensor response during closed-loop operation
• Emissions test failures tied to oxygen sensor faults
• Rough combustion control caused by aging sensor output

Installation Notes and Tips

Verify the connector shape, wire count, thread size, and downstream position before installation. Use the vehicle’s original mounting location and confirm the sensor seats fully on the threaded bung. Because this is a heated direct-fit oxygen sensor, inspect the harness routing and connector lock for proper engagement after installation. For fitment reference, Bosch 15238 fits 2016-2022 Chevrolet Camaro, downstream; 2015-2022 Chevrolet Colorado, downstream; and 2015-2022 GMC Canyon, downstream.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development and aftermarket supply experience. The design reflects Bosch’s OE-proven approach to sensor accuracy, heater control, and durability for demanding exhaust environments.