Denso 234-4849 Oxygen Sensor - Downstream or Downstream Right

Denso OE Style Oxygen Sensor 234-4849

Denso 234-4849 is an OE Style heated oxygen sensor built for direct replacement and precise signal control. It is engineered for specific-fit applications, including Audi S6, Audi A3 Quattro, Audi RS4, and Volkswagen Passat downstream positions.

The OE Style line focuses on exact replacement fitment and factory-style performance. Denso uses a ceramic element protected by an aluminum oxide trap layer to help resist silicone and lead contamination, supporting stable engine operation and consistent fuel control.

Key Features

• Heated oxygen sensor for faster operating response
• Specific fit design for direct replacement applications
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 27.20 in. wiring harness length
• OE Style construction for factory-style fit and function
• Built and tested to OE standards

Detailed Product Information

This Denso oxygen sensor, part number 234-4849, is designed for downstream monitoring on select Audi and Volkswagen applications. It is a heated sensor with a threaded mount and specific-fit connector layout, making it a direct replacement choice for vehicles that require OE-style sensor geometry and wiring length. The Denso 234-4849 is intended to restore accurate exhaust feedback for the engine management system on compatible downstream locations.

This part cross-references Bosch 16136 and NTK 25657 for the same application.

Vehicle Fitment

• Fits 2007-2011 Audi S6, downstream, Cylinder 6,7,8; OE Style
• Fits 2006-2009 Audi A3 Quattro, downstream right, OE Style
• Fits 2007-2008 Audi RS4, downstream, Cylinder 1,2,3,4; OE Style
• Fits 2006-2007 Volkswagen Passat, downstream right, OE Style

Common Issues This Sensor Can Address

• Fault codes related to downstream oxygen sensor performance
• Delayed or inaccurate exhaust oxygen readings
• Rough fuel control caused by a worn sensor element
• Reduced fuel economy from incorrect air-fuel feedback
• Check engine light concerns tied to sensor response or contamination

Installation Notes and Tips

Confirm the connector style, wire count, mounting thread, and downstream position before installation. For Audi S6, Audi A3 Quattro, Audi RS4, and Volkswagen Passat applications, verify the exact sensor location and cylinder or side notes listed in the fitment data. Inspect the harness routing and connector condition before connecting the new sensor.

Quality Assurance

Denso manufactures and tests this OE Style oxygen sensor to strict original-equipment standards. The design emphasizes first-time fit, stable operation, and contamination resistance for long service life.