Bosch 15788 Oxygen Sensor - Upstream

Bosch Wideband Oxygen Sensor for Mazda

Bosch Validated Oxygen Sensor 15788 is a specific-fit wideband air/fuel sensor for select Mazda applications. It delivers continuous, high-precision air-fuel ratio feedback to the ECU, helping maintain accurate mixture control across changing load and temperature conditions.

Built with Bosch’s planar pump-cell wideband design, this sensor supports fast response, stable heater performance, and dependable operation in demanding exhaust environments. It is a direct replacement choice for Mazda 3, Mazda 3 Sport, and Mazda 5 upstream applications where precise mixture monitoring matters.

Key Features

• Wideband A/F oxygen sensor for precise lambda measurement
• Specific-fit design with 5-wire harness and 6 terminals
• Heated sensor with optimized heater control for faster light-off
• Threaded mounting with 18 mm thread diameter and 22 mm hex size
• Metal housing and robust ceramic construction for durability
• Wiring harness included; harness length measures 17.1 in
• Overall length: 20.7 in; sealing surface to connector end: 19.5 in

Product Details

Bosch Validated Oxygen Sensor 15788 is part of the Bosch Validated Oxygen Sensor line, a standard replacement range built around OE development experience and Bosch’s wideband sensor technology. This sensor provides the ECU with detailed air-fuel ratio data across the full lambda range, which is especially important for modern engine management systems that rely on accurate upstream feedback. This part cross-references Monroe Shocks & Struts (e.g., LF3T188G1, LF8R188G1A) for the same application.

Compatible With 2012-2013 Mazda 3, Upstream; 2012-2013 Mazda 3 Sport, Upstream; 2010-2011 Mazda 3, Upstream with California Emission System; 2006-2011 Mazda 3, Upstream without California Emission System; and 2008-2010 Mazda 5, Upstream. Bosch 15788 is a direct-fit option for Mazda 3 and Mazda 5 owners replacing an upstream wideband sensor.

Common Issues This Sensor Can Address

• Fault codes related to upstream air-fuel ratio sensor performance
• Rough idle caused by inaccurate mixture feedback
• Reduced fuel economy from incorrect fuel trim control
• Hesitation or inconsistent throttle response under load
• Emissions test failures tied to sensor signal degradation

Installation Notes

Verify the connector shape, terminal count, thread size, and upstream location before installation. This sensor uses a rectangular male connector, blade terminals, and a threaded mount; confirm the vehicle’s emission configuration on 2010-2011 Mazda 3 applications, since California and non-California systems use different fitments. Use proper oxygen sensor service tools and follow the vehicle manufacturer’s torque and routing specifications.

Quality Assurance

Bosch has more than five decades of OE development experience and supplies oxygen sensors built to OE-proven standards for aftermarket replacement. Bosch Validated Oxygen Sensor 15788 reflects that engineering background with a wideband design intended for accurate, reliable upstream air-fuel measurement.