Denso 234-4043 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor for Mazda 626

This Denso oxygen sensor is an OE Style, specific-fit replacement for downstream applications on the 2000-2002 Mazda 626. Built to match factory fit and electrical requirements, Denso 234-4043 is a direct option for restoring accurate exhaust feedback in the emissions system.

Key Features

• Heated oxygen sensor with a 4-wire design for stable signal performance
• Specific fit for direct replacement on listed Mazda 626 applications
• Threaded mounting type with a 0.708 in. thread diameter
• 16.93 in. wiring harness length for proper routing
• Female connector for OE-style electrical connection
• OE Style construction focused on first-time fit and factory-level replacement
• Aluminum oxide trap layer helps protect the sensing element from silicone and lead contamination

Product Details

Denso 234-4043 is engineered for downstream use on the Mazda 626, with fitment listed for 2000 Mazda 626 downstream and 2001-2002 Mazda 626 downstream. The heated sensor design supports quicker operating temperature, while the specific-fit configuration helps simplify replacement on the correct exhaust location. This part cross-references Bosch 15265 and NTK 22104 for the same application.

Denso’s OE Style line is built around exact replacement dimensions and tested to OE standards. That approach matters for a Mazda 626 oxygen sensor replacement because proper sensor response affects fuel control, emissions monitoring, and drivability. The protective trap layer adds durability by helping shield the ceramic element from common contamination sources in the exhaust stream.

Common Issues This Part May Address

• Check engine light related to downstream oxygen sensor performance
• Incorrect exhaust oxygen readings affecting emissions system operation
• Reduced fuel efficiency caused by inaccurate sensor feedback
• Rough or inconsistent engine operation tied to sensor degradation
• Failed emissions inspection due to a worn or contaminated sensor

Installation Notes and Tips

Verify the downstream location before installation and confirm connector style, wire count, and thread size against the original sensor. On 2000-2002 Mazda 626 applications, route the harness away from hot exhaust surfaces and inspect the connector for corrosion or damaged terminals before plugging in the replacement. Use the vehicle’s service procedure for proper removal and tightening.

Quality Assurance

Denso manufactures and tests this OE Style oxygen sensor to strict original-equipment standards for fit and performance. The design focus on exact replacement dimensions and contamination resistance supports consistent operation in Mazda 626 downstream applications.