Bosch 15426 Oxygen Sensor - Downstream, Downstream Rear or Downstream Right

Bosch Validated Oxygen Sensor for Mazda

Bosch 15426 is a specific-fit narrow-band heated oxygen sensor for downstream applications on select Mazda vehicles. It provides air-fuel-ratio feedback to the ECU for stable closed-loop control and emissions monitoring, with a threaded metal housing and a 4-wire harness for direct replacement service.

Key Features

• Bosch Validated Oxygen Sensor, part number 15426
• Narrow-band heated O2 sensor for downstream use
• Specific fit with 4-wire, blade-terminal harness
• Threaded 18 mm sensor body with 22 mm hex size
• Metal housing with square male connector
• Wiring harness included; harness length 21.8 in
• Overall length 25.2 in; sealing surface to connector end 24 in

Detailed Description

Bosch 15426 is built for Mazda 6 and Mazda 626 downstream oxygen sensor replacement where precise exhaust feedback is needed for fuel control and emissions management. Bosch’s validated oxygen sensor line draws on decades of OE development, using ceramic sensing elements, controlled heater operation, and high-temperature materials to maintain consistent signal output under heat and vibration. This part number 15426 is a direct-fit solution for select 2000-2008 Mazda applications, including Mazda 6 downstream rear and downstream positions, plus Mazda 626 downstream rear and downstream right listings.

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

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough idle or unstable closed-loop fuel control
• Emissions test failures tied to downstream sensor faults
• Slow sensor response after converter or exhaust service

Installation Notes and Tips

Verify the connector shape, wire count, and threaded 18 mm sensor specification before installation. This Bosch 15426 oxygen sensor is a specific-fit replacement for downstream Mazda 6 and Mazda 626 applications listed in the fitment data, including California-emissions configurations where noted. Use proper oxygen sensor service tools and confirm the sensor seats fully at the threaded mounting point.

Quality Assurance

Bosch backs this Validated Oxygen Sensor line with OE development experience and application-focused validation for aftermarket replacement. The design uses durable materials and heater control strategies intended to maintain accurate signal output across demanding operating conditions.