Bosch 15386 Oxygen Sensor - Downstream

Bosch Validated Oxygen Sensor for Mazda 6

Bosch Part Number 15386 is a specific-fit, downstream narrow-band heated oxygen sensor for select 2006-2008 Mazda 6 applications. It measures exhaust oxygen content and sends precise air-fuel-ratio data to the ECU to support stable closed-loop fuel control and lower emissions.

The Bosch Validated Oxygen Sensor line focuses on OE-style replacement fitment and validated application coverage. For Mazda 6 owners searching for a downstream O2 sensor replacement, Bosch 15386 offers the connector, harness, and threaded mounting style needed for a direct service repair.

Key Features

• Specific-fit Bosch oxygen sensor for downstream placement
• Narrow-band heated sensor design for closed-loop operation
• 4-wire configuration with included wiring harness
• Rectangle female connector with female terminals
• Threaded mounting, 18 mm thread size, 22 mm hex size
• Metal housing built for high-temperature and vibration exposure
• Overall length: 23 in; harness length: 19.6 in

Detailed Description

Bosch 15386 is a standard replacement oxygen sensor engineered for Mazda 6 exhaust systems that use a downstream narrow-band heated sensor. Bosch’s OE development background is reflected in the sensor’s ceramic element, heater control strategy, and durable materials, which help maintain accurate lambda feedback under changing exhaust temperatures. This part cross-references Monroe Shocks & Struts (e.g., L39418861A) for the same application.

Compatible With 2006-2008 Mazda 6, downstream, including configurations with California Emission System and vehicles located after the secondary converter where noted in the fitment data. Bosch Part Number 15386 is also listed for 2008 Mazda 6 downstream service applications.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Rich or lean fuel trim conditions caused by inaccurate exhaust feedback
• Slow closed-loop response after sensor aging or contamination
• Emissions test failures tied to downstream sensor faults
• Rough combustion control from degraded air-fuel ratio measurement

Installation Notes and Tips

Confirm the downstream location before ordering, since this sensor is used after the secondary converter on listed Mazda 6 applications. Verify the 4-wire connector style, 18 mm thread size, and 22 mm hex size against the original sensor before installation. 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 and supplies validated replacement sensors built to the same application standards used by vehicle manufacturers. Bosch Part Number 15386 is backed by Bosch’s OE-focused engineering and application validation for the listed Mazda 6 fitments.