Bosch 15138 Oxygen Sensor - Downstream

Reliable Oxygen Sensor for BMW M3, Z3, and Z4

The Bosch Actual OE Oxygen Sensor 15138 is designed specifically for select BMW models including the M3, Z3, and Z4. This narrow-band heated oxygen sensor ensures accurate air-fuel mixture readings to support optimal engine performance and emissions control.

• Specific fit for BMW M3, Z3, and Z4 models
• Heated narrow-band oxygen sensor for precise monitoring
• Threaded mounting type with 18 mm thread diameter and 22 mm hex size
• Includes 38.6-inch wiring harness with 4-pin female connector
• Durable metal housing finished in steel for long-lasting use
• Standard replacement grade for reliable performance

About the Bosch Actual OE Oxygen Sensor Line

The Bosch Actual OE Oxygen Sensor product line focuses on delivering direct-fit replacement sensors that meet original equipment specifications. This ensures compatibility and performance consistency for vehicles like the BMW M3, Z3, and Z4. The 15138 part number sensor is engineered to provide accurate oxygen level readings with a heated element to reduce warm-up time and improve emissions control.

Detailed Product Features and Specifications

This Bosch oxygen sensor features a narrow-band sensor type with a heated element to maintain accurate readings under various operating conditions. The sensor is threaded with an 18 mm diameter and includes a 22 mm hex size for installation using standard tools. The wiring harness length is 38.6 inches, terminating in a 4-pin female connector with a round shape, designed for a specific fit on compatible BMW models. The sensor’s metal housing finished in steel offers durability and resistance to harsh engine environments. Weighing approximately 0.34 pounds, it is a standard replacement grade part that includes the wiring harness for a complete installation.

Common Applications and Issues Addressed

• Restores accurate air-fuel ratio readings for improved engine efficiency
• Helps resolve check engine light triggers related to oxygen sensor faults
• Reduces emissions by ensuring proper catalytic converter function
• Improves fuel economy by providing precise sensor data to the engine control unit
• Eliminates rough idling or poor acceleration caused by faulty oxygen sensors

Installation Notes and Tips

Installation requires a 22 mm oxygen sensor socket or wrench. Ensure the engine is cool before removal to avoid injury. The threaded sensor mounts securely with an 18 mm thread diameter. The 4-pin female connector should be matched carefully to the vehicle’s wiring harness to avoid damage. No mounting bracket is included, so use the existing mounting location on the vehicle. Verify compatibility with BMW M3, Z3, or Z4 models before installation.

Quality Assurance and Warranty

Bosch oxygen sensors are manufactured to meet strict quality standards and original equipment specifications. The Actual OE Oxygen Sensor 15138 undergoes rigorous testing to ensure reliable performance and durability. While specific warranty details may vary, Bosch typically offers a limited warranty covering defects in materials and workmanship for this sensor.