Denso 234-4120 Oxygen Sensor - Downstream

Reliable Oxygen Sensor for Audi Quattro Models

The Denso OE Style Oxygen Sensor 234-4120 is designed specifically for select Audi Quattro vehicles, including the A4, A5, A6, A7, A8, Q5, S4, S5, and SQ5. This heated oxygen sensor ensures accurate emissions monitoring and optimal engine performance by providing precise air-fuel mixture data.

• Heated sensor type for faster response times
• Specific fit for Audi Quattro models
• Threaded mounting type with 0.708 inch thread diameter
• 19.69-inch wiring harness length with 4 wires
• Male connector for secure electrical connection

About the Denso OE Style Product Line

The OE Style line from Denso offers direct replacement parts engineered to meet original equipment specifications. The 234-4120 oxygen sensor maintains factory-level quality and fitment, ensuring compatibility and reliable performance for Audi Quattro vehicles. This product line focuses on precise fit and function, making it suitable for professional repairs and maintenance.

Product Details and Specifications

This oxygen sensor features a heated design that accelerates sensor activation, reducing warm-up time and improving emissions control. The 19.69-inch wiring harness provides adequate length for installation without excess slack. With four wires and a male connector, the sensor integrates seamlessly with the vehicle’s existing wiring harness. The threaded mounting type with a 0.708-inch diameter ensures a secure and proper fit in the exhaust system.

Common Applications and Issues Addressed

• Restores accurate air-fuel ratio readings for Audi A4 Quattro and other compatible models
• Helps resolve check engine light triggers related to oxygen sensor faults
• Improves fuel efficiency by providing precise emissions data
• Reduces exhaust emissions by maintaining proper sensor function
• Prevents rough idling and engine performance issues caused by faulty sensors

Installation Notes and Tips

Ensure the vehicle is cool before removing the old oxygen sensor to avoid burns. Use appropriate tools to avoid damaging the threaded mounting. Verify the connector gender matches the vehicle harness for a secure connection. Follow manufacturer torque specifications when installing the sensor to prevent leaks or damage.

Quality Assurance and Warranty

Denso OE Style oxygen sensors are manufactured to meet strict quality standards and original equipment specifications. The 234-4120 part number undergoes rigorous testing to ensure durability and reliable performance. Warranty coverage details should be confirmed with the point of purchase or manufacturer documentation.