Denso 234-4646 Oxygen Sensor - Downstream or Upstream

Denso OE Style Oxygen Sensor 234-4646

Denso 234-4646 is an OE-style heated oxygen sensor built for exact replacement and first-time fit. It is engineered for upstream applications on select Buick, Chevrolet, GMC, Oldsmobile, Pontiac, and Saturn vehicles, including Buick Allure, Chevrolet Cobalt, and Pontiac Grand Prix applications.

Denso’s OE Style line focuses on direct-fit replacement parts that match factory specifications. This oxygen sensor uses a threaded mounting design, a female connector, 4 wires, and a 12.99-inch wiring harness length for a specific-fit installation.

Key Features

• Heated oxygen sensor for upstream emission control applications
• Specific-fit design for direct replacement on listed vehicles
• 4-wire configuration with female connector
• Threaded mounting type with 0.708-inch thread diameter
• 12.99-inch wiring harness length
• Built to OE standards for accurate replacement fitment
• Aluminum oxide trap layer helps protect the ceramic element from silicone and lead contamination

Product Details

This Denso oxygen sensor is designed to monitor exhaust oxygen content and support proper fuel control in the engine management system. It is a direct replacement for upstream sensor locations on many GM platforms, including 2005-2009 Buick Allure, 2005-2007 Chevrolet Cobalt, 2004-2007 Pontiac Grand Prix, and 2003-2007 Saturn Ion. The part number 234-4646 is also referenced in OE-style replacement searches for these applications.

This part cross-references Bosch 13455 and NTK 21045 for the same application.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel mixture readings
• Poor fuel economy caused by a failing upstream sensor
• Slow or inaccurate sensor response
• Emissions test failures tied to sensor degradation

Installation Notes

Verify the connector style, wire count, thread diameter, and sensor position before installation. This sensor is listed for upstream locations only on the vehicles shown in the fitment data. Confirm the exact year, make, model, and emissions configuration before ordering, especially for applications noted as excluding California.

For best results, inspect the harness routing and connector condition during replacement. The OE-style design is intended to match factory fitment on the listed Buick, Chevrolet, Pontiac, Saturn, GMC, and Oldsmobile applications.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for precise replacement fit and dependable operation. The 234-4646 is part of Denso’s OE Style line, which is built to deliver the correct part and fit for the listed applications.