Denso 234-4664 Oxygen Sensor - Downstream or Upstream

Denso OE Style Oxygen Sensor 234-4664

Denso 234-4664 is a heated, specific-fit oxygen sensor built for direct replacement in select Audi and Volkswagen applications. It is engineered to match OE-style fitment and signal performance for accurate exhaust monitoring and dependable drivability.

Key Features

• Heated oxygen sensor for faster operating temperature and stable feedback
• Specific fit design for direct replacement on listed applications
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 30.91 in. wiring harness length for proper routing
• OE Style product line focused on factory-like fit and function

OE Style Design and Construction

The Denso OE Style line is built for exact replacement applications where factory-style fit and connector compatibility matter. This oxygen sensor uses Denso’s ceramic protection approach to help reduce contamination from silicone and lead exposure, supporting consistent exhaust readings and long service life. Part number 234-4664 is a direct-fit option for drivers servicing emissions and fuel-control systems on Audi A4, Audi A6, Audi A8, Volkswagen Jetta, Volkswagen Passat, Volkswagen Golf, and Volkswagen EuroVan models listed below.

This part cross-references Bosch 13736 and NTK 25550 for the same application.

Vehicle Fitment

• Fits 1997-2000 Audi A4 Quattro, downstream.
• Fits 1997-1999 Audi A4, upstream.
• Fits 1997-1999 Audi A4, downstream.
• Fits 1998-1999 Audi A4 Quattro, upstream.
• Fits 1999 Audi A6, upstream.
• Fits 1998 Audi A6, upstream, from serial #4B-W-000 001.
• Fits 1999 Audi A6 Quattro, upstream.
• Fits 1998 Audi A6 Quattro, upstream, from serial #4B-W-000 001.
• Fits 1997-1999 Audi A8, upstream.
• Fits 1997-1999 Audi A8 Quattro, upstream.
• Fits 1995-1998 Volkswagen Golf, upstream.
• Fits 1995-1999 Volkswagen Passat, upstream.
• Fits 1998-1999 Volkswagen Passat, downstream.
• Fits 1995 Volkswagen Jetta, upstream.
• Fits 1996 Volkswagen Jetta, upstream, from chassis #1H-T-000 001.
• Fits 1997-1999 Volkswagen Jetta, upstream.
• Fits 1997 Volkswagen EuroVan, upstream.
• Fits 1999-2000 Volkswagen EuroVan, upstream.

Common Issues This Sensor Can Address

• Faulty oxygen sensor readings that trigger emissions-related trouble codes
• Rough idle or inconsistent air-fuel control caused by a worn sensor
• Reduced fuel economy from delayed or inaccurate exhaust feedback
• Slow sensor response during warm-up in heated sensor applications
• Replacement needs after contamination or age-related sensor degradation

Installation Notes and Tips

Confirm the connector style, wire count, thread size, and sensor position before installation. This is a specific-fit oxygen sensor for threaded mounting, so routing the 30.91 in. harness correctly is important for a clean install on the listed Audi and Volkswagen applications. Verify upstream or downstream placement against the vehicle’s original sensor location and match any chassis or serial-number notes shown in the fitment data.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for factory-style replacement performance. The OE Style line is designed to deliver the right fit and the right part for the listed applications, with construction focused on consistent operation and long-term durability.