Bosch 15330 Oxygen Sensor - Downstream, Upstream, Upstream Rear or Upstream Right

Bosch Validated Oxygen Sensor for Mazda and Kia

Bosch Validated Oxygen Sensor 15330 is a specific-fit narrow-band heated O2 sensor built for precise air-fuel-ratio feedback to the ECU. It supports stable combustion control and emissions management for select Mazda, Kia, Ford, and Mercury applications, including Mazda Miata, Mazda Protege, Mazda 626, and Mazda MX-3.

Key Features

• Specific-fit Bosch Validated Oxygen Sensor for direct application matching
• Narrow-band heated design for faster closed-loop operation
• 4-wire configuration with rectangular female connector
• Threaded mounting with 18 mm thread size and 22 mm hex
• Wiring harness included with 24.2 in harness length
• Metal housing and high-temperature-resistant construction for demanding exhaust conditions

How Bosch Validated Oxygen Sensor 15330 Works

Bosch 15330 uses a switching-type narrow-band sensing element to report oxygen content in the exhaust stream so the engine control unit can adjust fuel delivery accurately. Bosch’s oxygen sensor development traces back to its original OE work in 1976, and this validated replacement continues that focus with ceramic sensing technology, controlled heater performance, and materials selected for thermal and vibration resistance. This makes it a practical replacement for vehicles that need dependable upstream or downstream O2 sensor feedback, including Mazda Miata and Mazda Protege applications.

This part cross-references Bosch Validated Oxygen Sensor (e.g., BP3A188619U, BP4X18861A9U) for the same application.

Common Problems This Sensor Can Address

• Check engine light related to oxygen sensor performance
• Rich or lean fuel trim readings caused by inaccurate exhaust feedback
• Slow closed-loop response after startup
• Emissions test failures tied to sensor degradation
• Rough idle or inconsistent fuel control from a worn narrow-band sensor

Installation Notes and Fitment

Install as a threaded oxygen sensor using the correct 18 mm thread and 22 mm hex. Verify connector style, wire count, and sensor position before installation. Compatible with these confirmed applications:

• Fits 2000 Mazda 626, downstream, located after secondary converter; without California Emission System.
• Fits 1998-1999 Mazda 626, downstream, located after secondary converter; Bosch Engineered Oxygen Sensor.
• Fits 1998-1999 Mazda 626, downstream; without California Emission System.
• Fits 1999-2000 Mazda Miata, upstream.
• Fits 1994-1997 Mazda Miata, upstream.
• Fits 1999-2000 Mazda Miata, downstream; with California Emission System.
• Fits 1999-2000 Mazda Protege, upstream; alternative fit 1.
• Fits 1995-1998 Mazda Protege, upstream; alternative fit 1.
• Fits 1995-1997 Kia Sephia, upstream; alternative fit 1.
• Fits 1995-1996 Ford Escort, upstream; alternative fit 1.
• Fits 1995-1996 Mercury Tracer, upstream; alternative fit 1.
• Fits 1995 Mazda MX-3, upstream rear; alternative fit 1.
• Fits 1994 Mazda MX-3, upstream right; without California Emission System; alternative fit 1.
• Fits 1992-1993 Mazda MX-3, upstream right; alternative fit 1.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development and aftermarket supply experience. Bosch Validated Oxygen Sensor 15330 is engineered to deliver OE-proven fit and signal performance for the listed Mazda, Kia, Ford, and Mercury applications.