Denso 234-4661 Oxygen Sensor - Downstream or Downstream Right

Denso OE Style Oxygen Sensor 234-4661

Denso 234-4661 is an OE Style heated oxygen sensor built for direct replacement in specific applications. It is engineered for exact fitment and stable exhaust feedback, helping maintain proper air-fuel control in vehicles such as Audi A4, Audi A6, Volkswagen Passat, and Acura RLX.

The OE Style line focuses on first-time fit and factory-style replacement dimensions. This sensor uses a threaded mounting design, a male connector, 4 wires, and a 67.72-inch wiring harness for the specified downstream positions.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific fit design for direct replacement
• Threaded mounting type with 0.708-inch thread diameter
• 4-wire configuration with male connector
• 67.72-inch wiring harness length
• Built to OE standards for replacement accuracy
• Aluminum oxide trap layer helps protect the ceramic element from silicone and lead contamination

Product Details

Denso’s OE Style oxygen sensor line is built and tested to OE-level standards for consistent signal performance and accurate replacement fit. Part number 234-4661 is designed for downstream use on select Audi, Volkswagen, and Acura applications, including 1994-1999 Audi Cabriolet, 1996-1999 Audi A4 and A4 Quattro, 1998-1999 Audi A6 and A6 Quattro, 1998-1999 Volkswagen Passat, and 2019 Acura RLX downstream right. This part cross-references Bosch 13550 and NTK 25552 for the same application.

What This Sensor Helps Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback from a worn downstream sensor
• Reduced fuel economy caused by inaccurate exhaust readings
• Slow or inconsistent sensor response during closed-loop operation
• Replacement needs for a damaged or aging OE-style sensor

Installation Notes and Tips

Verify the connector style, wire count, thread diameter, and downstream position before installation. For fitment, this part fits 1994-1998 Audi Cabriolet, downstream; 1996-1999 Audi A4, downstream; 1996-1999 Audi A4 Quattro, downstream; 1998-1999 Volkswagen Passat, downstream; and 2019 Acura RLX, downstream right. On 1998 Audi A6 and A6 Quattro, confirm the serial number note before ordering. Use the vehicle’s original routing and mounting points to keep the harness away from heat and moving components.

Quality Assurance

Denso manufactures and tests this oxygen sensor to strict OE standards, with precision-built dimensions for direct replacement and a first-time fit. The OE Style design and protective trap layer support long-term sensor durability in demanding exhaust environments.