Denso 234-4330 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-4330

Denso 234-4330 is a specific-fit heated oxygen sensor built for direct replacement on select Mazda applications. It is engineered for the 2001-2005 Mazda Miata downstream position, with OE-style fitment and a 4-wire, threaded design for accurate exhaust monitoring.

The Denso OE Style line focuses on exact replacement fit and factory-level sensor performance. This oxygen sensor uses Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination, supporting stable engine operation and consistent fuel control over time.

Key Features

• Specific-fit heated oxygen sensor for direct replacement
• Fits 2001-2005 Mazda Miata, downstream
• OE Style design for factory-like fit and function
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 39.76 in. wiring harness length
• Denso part number 234-4330

Detailed Description

This Denso oxygen sensor is built to OE standards for vehicles that rely on precise exhaust feedback to manage air-fuel ratio and emissions performance. For Mazda Miata downstream oxygen sensor replacement, part number 234-4330 provides the correct specific-fit configuration and connector style for a clean installation and proper system communication. It is also cross-referenced to Bosch 13866 for the same application.

As part of Denso’s OE Style product line, this sensor is designed as a direct replacement solution rather than a universal unit. That makes it a strong match for drivers searching for a 2001-2005 Mazda Miata downstream oxygen sensor, Denso 234-4330, or an OE-style heated O2 sensor for Mazda Miata exhaust service.

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect exhaust oxygen readings affecting fuel control
• Reduced fuel economy caused by a worn sensor
• Slow sensor response from contamination or age
• Emissions test failures tied to oxygen sensor performance

Installation Notes and Tips

Verify the downstream location before installation and confirm connector style, thread diameter, and harness length against the original sensor. Because this is a specific-fit threaded sensor, proper routing of the 39.76 in. harness helps prevent strain, heat damage, or contact with exhaust components. Always inspect the connector and wiring condition before final installation.

Quality Assurance

Denso manufactures and tests this oxygen sensor to strict OE standards for replacement accuracy and consistent performance. The sensor’s aluminum oxide trap layer adds protection against silicone and lead contamination, supporting long-term durability in demanding exhaust environments.