Denso 234-4874 Oxygen Sensor - Downstream or Upstream

OE Style Oxygen Sensor for Audi and Volkswagen

Denso OE Style Oxygen Sensor 234-4874 is a direct-fit, heated sensor built for specific applications in Audi and Volkswagen vehicles. It is engineered for accurate exhaust monitoring, stable signal output, and a first-time fit on the listed downstream and upstream positions.

Designed for 1998-2009 Audi A4, A4 Quattro, A6, A6 Quattro, TT, TT Quattro, Allroad Quattro, S4, and Audi A8 Quattro, as well as Volkswagen Golf, Jetta, Passat, Beetle, Cabrio, EuroVan, Phaeton, and Touareg applications, this sensor supports proper air-fuel control and emissions system operation. Part number 234-4874 is also a direct OE-style replacement for service work where exact connector and thread specifications matter.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for direct replacement on listed vehicles
• 4-wire configuration with male connector
• Threaded mounting type with 0.708 in. thread diameter
• 69.21 in. wiring harness length for application-specific routing
• Built to OE standards for fit, function, and durability
• Aluminum oxide trap layer helps protect the sensing element from silicone and lead contamination

OE Style Construction

Denso’s OE Style line focuses on exact replacement parts that match the original sensor’s fit and operating characteristics. The sensor element is precision built for the listed applications, helping maintain consistent exhaust feedback for engine management systems. If you are replacing a downstream oxygen sensor on an Audi A4 Quattro or a Volkswagen Passat, or servicing an upstream sensor on a Volkswagen Jetta or Cabrio, 234-4874 is built for the specified position and connector style.

This part cross-references Bosch 16978 and NTK 25605 for the same application.

What This Sensor Helps Address

• Check engine light concerns related to oxygen sensor performance
• Incorrect air-fuel ratio feedback from a worn sensor
• Reduced fuel economy caused by slow or inaccurate sensor response
• Emissions test failures tied to faulty exhaust monitoring
• Driveability issues from contaminated or aging sensor elements

Installation Notes and Fitment

Compatible with specific Audi and Volkswagen applications only. Confirm the sensor position before ordering: this part is listed for downstream and upstream locations depending on the vehicle. Fits 2000-2006 Audi A4, downstream; fits 2000 Audi A4, upstream; fits 2000-2005 Audi A4 Quattro, downstream; fits 2000 Audi A4 Quattro, upstream; fits 2002-2004 Audi A6, downstream; fits 2002-2004 Audi A6 Quattro, downstream; fits 2002-2005 Audi Allroad Quattro, downstream; fits 2004-2009 Audi S4, downstream; fits 2001-2006 Audi TT, downstream; fits 2000-2001 Audi TT, upstream; fits 2000 Audi TT Quattro, upstream and downstream; fits 2001 Audi TT Quattro, downstream; fits 1998-2001 Volkswagen Beetle, upstream; fits 2001-2004 Volkswagen Beetle, downstream; fits 2000-2002 Volkswagen Cabrio, upstream and downstream; fits 2001-2003 Volkswagen EuroVan, downstream; fits 1999-2001 Volkswagen Golf, upstream; fits 1999-2006 Volkswagen Golf, downstream; fits 1999-2001 Volkswagen Jetta, upstream; fits 2004 Volkswagen Jetta, upstream from chassis #9M-4-000 001; fits 1999-2005 Volkswagen Jetta, downstream; fits 2000-2005 Volkswagen Passat, upstream and downstream; fits 2004-2006 Volkswagen Phaeton, downstream; fits 2004-2007 Volkswagen Touareg, downstream.

Use the connector, wire count, and thread specifications to verify match-up before installation. For Audi A4, Audi TT, and Volkswagen Jetta service, confirm whether the vehicle calls for an upstream or downstream sensor and compare the original part number to the replacement.

Quality Assurance

Denso manufactures and tests these oxygen sensors to OE standards for consistent replacement performance. The design includes contamination protection for the sensing element, supporting long service life and stable operation in emissions control systems.