Denso 234-4329 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-4329

This Denso OE Style oxygen sensor is a direct-fit replacement built for precise signal control and dependable exhaust monitoring. It is engineered for specific applications, including Mazda 2, Mazda 3, and Mazda 6 downstream positions, with fitment matched to the vehicle and location.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for direct replacement installation
• 4-wire configuration with female connector
• Threaded mounting with 0.708 in. thread diameter
• 32.48 in. wiring harness length for application-specific routing
• OE Style construction for Mazda downstream sensor applications

Product Details

Denso Part Number 234-4329 is part of the OE Style line, which focuses on exact replacement fit and factory-style performance. Denso manufactures and tests these oxygen sensors to OE standards, using precision-built components for consistent installation and reliable exhaust feedback. The sensor also uses Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination, supporting long-term durability in demanding exhaust environments. This part cross-references Bosch 15371 and NTK 25670 for the same application.

Compatible With 2011-2014 Mazda 2, downstream; 2004-2009 Mazda 3, downstream; and 2006-2008 Mazda 6, downstream. Searchers looking for a Mazda 3 downstream oxygen sensor, Mazda 6 downstream O2 sensor, or Denso 234-4329 replacement will find this OE-style option matched to the listed vehicles.

What It Helps Address

• Check engine light concerns related to oxygen sensor performance
• Incorrect air-fuel feedback from a worn downstream sensor
• Reduced fuel economy caused by inaccurate exhaust readings
• Emissions test failures tied to sensor response issues
• Hard-to-match replacement fit on Mazda downstream applications

Installation Notes

Verify the connector style, wire count, thread diameter, and downstream location before installation. This sensor uses a threaded mount and a female connector, so the existing harness and exhaust bung should be checked for matching configuration. For Mazda 2, Mazda 3, and Mazda 6 applications, confirm the exact model year and downstream position listed above before ordering.

Quality Assurance

Denso builds this oxygen sensor to strict OE standards and tests each component for replacement accuracy and first-time fit. The OE Style line is designed to deliver factory-matched performance for the specified Mazda applications.