Bosch 13885 Oxygen Sensor - Downstream

Bosch Oxygen Sensor for Mazda Protege

Bosch Part Number 13885 is a specific-fit, narrow-band heated oxygen sensor for downstream applications on select Mazda Protege models. It uses a 4-wire, threaded design with a 22 mm hex and included wiring harness to support accurate air-fuel ratio feedback to the ECU.

Built under the Bosch Engineered Oxygen Sensor line, this sensor reflects Bosch’s long OE development history in oxygen sensing technology. The design uses a ceramic sensing element, controlled heater operation, and high-temperature materials for stable closed-loop performance in demanding exhaust conditions.

Key Features

• Fits 2001-2003 Mazda Protege, downstream
• Fits 1999-2000 Mazda Protege, downstream, with California Emission System
• Bosch Part Number 13885
• Narrow-band heated oxygen sensor
• 4-wire configuration with rectangular connector
• Threaded mounting with 18 mm thread size and 22 mm hex
• Specific-fit replacement with wiring harness included
• Metal housing with steel finish

Product Details

Bosch Engineered Oxygen Sensor products are developed from Bosch’s original oxygen sensor work and later planar narrowband designs that improved response time and closed-loop operation. For Mazda Protege downstream service, Bosch 13885 provides the signal the engine control unit uses to monitor exhaust oxygen content and maintain proper combustion control. This part cross-references Monroe Shocks & Struts (e.g., ZM0218861A9U) for the same application.

Common Issues This Sensor Can Help Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio readings at the ECU
• Rough idle or unstable closed-loop fuel control
• Increased emissions from a worn downstream sensor
• Delayed sensor response from heat or age-related wear

Installation Notes and Tips

Verify downstream placement before installation and confirm the vehicle’s emission configuration, especially on 1999-2000 Mazda Protege models with California Emission System. The sensor uses an 18 mm thread and 22 mm hex, so the correct oxygen sensor socket or wrench is recommended. Inspect the connector, harness routing, and exhaust threads before final tightening.

Quality Assurance

Bosch supplies oxygen sensors with OE-proven engineering and durable materials selected for high exhaust temperatures and vibration exposure. Bosch Part Number 13885 is built as a standard replacement sensor for direct-fit service on the listed Mazda Protege applications.