Bosch 15429 Oxygen Sensor - Downstream or Downstream Rear

Bosch Validated Oxygen Sensor for Mazda Applications

Bosch Validated Oxygen Sensor Part Number 15429 is a specific-fit, narrow-band heated O2 sensor built for accurate air-fuel-ratio feedback to the ECU. It is a direct replacement choice for select Mazda 3, Mazda 3 Sport, and Mazda 6 applications with downstream or downstream rear placement.

Key Features

• Specific-fit Bosch oxygen sensor for targeted vehicle applications
• Narrow-band heated sensor design for closed-loop fuel control
• 4-wire configuration with blade terminals and square connector
• Threaded mounting with 18 mm thread size and 22 mm hex size
• Wiring harness included with 12.9 in harness length
• Metal housing built for high-temperature and vibration exposure
• Standard replacement grade for emission control service

Product Details

Bosch Part Number 15429 uses a switching-type oxygen sensor design to send precise exhaust oxygen feedback to the engine control unit. Bosch developed this sensor line from its long OE oxygen sensor history, including planar narrowband technology that improves light-off response and closed-loop operation. For drivers servicing a Mazda 3, Mazda 3 Sport, or Mazda 6, this sensor supports stable combustion control and emission system performance in the downstream or downstream rear position.

Bosch Validated Oxygen Sensor Part Number 15429 cross-references AJ6018861B and PE081886ZA for the same application.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback to the ECU
• Rough idle or inconsistent fuel control from a worn downstream sensor
• Emission test failures tied to sensor response issues
• Slow closed-loop operation after sensor aging or contamination

Installation Notes and Tips

Verify the connector shape, wire count, thread diameter, and sensor position before installation. This Bosch 15429 sensor is a threaded, heated narrow-band unit with a square male connector and included harness, so matching the original routing and connector style is important. Confirm fitment for 2012-2013 Mazda 3 and Mazda 3 Sport downstream locations, or 2003-2005 Mazda 6 downstream rear locations, before replacing the original sensor.

Quality Assurance

Bosch has decades of OE oxygen sensor development behind this Validated Oxygen Sensor line, with ceramic sensing elements, controlled heater operation, and materials selected for demanding exhaust temperatures. The result is an OE-proven replacement option for Mazda emission control service.