Denso 234-4190 Oxygen Sensor - Downstream, Upstream or Upstream Rear

Denso OE Style Oxygen Sensor 234-4190

Denso 234-4190 is an OE Style heated oxygen sensor built for exact replacement and first-time fit. It is engineered for specific applications on the Mazda 6 and Kia Rio, with the connector, thread, and harness layout matched to the original sensor.

The OE Style line is designed around factory-fit accuracy, making this Denso oxygen sensor a direct choice for drivers replacing a worn upstream or downstream sensor on select Mazda 6 and Kia Rio models.

Key Features

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

Detailed Description

This Denso oxygen sensor, part number 234-4190, is manufactured and tested to OE-style standards for accurate replacement on emissions control systems. It is a heated, threaded sensor with a specific-fit design, 4-wire construction, and a male connector, helping ensure the sensor matches the original mounting and electrical connection on the vehicle. The aluminum oxide trap layer is used to help shield the sensing element from contamination, supporting stable engine management and fuel control over time.

Compatible With 2003-2008 Mazda 6, upstream rear; 2004-2005 Kia Rio, upstream; and 2004-2005 Kia Rio, downstream. This part cross-references Bosch (e.g., 15431, 15647) for the same application. Search terms such as Mazda 6 upstream rear oxygen sensor, Kia Rio downstream oxygen sensor, and Denso 234-4190 OE style replacement sensor align with this application.

What It Helps Address

• Check engine light caused by a failing oxygen sensor
• Incorrect air-fuel mixture readings
• Reduced fuel economy from aging sensor response
• Emissions test failures related to sensor performance
• Rough idle or drivability issues tied to faulty exhaust feedback

Installation Notes and Tips

Verify the sensor position before ordering, since this part is listed for upstream rear, upstream, and downstream locations depending on the vehicle. Confirm the connector style, thread diameter, and harness length against the original sensor before installation. For best results, inspect the wiring route and exhaust threads for damage or contamination before fitting the new sensor.

Quality Assurance

Denso manufactures this OE Style oxygen sensor to strict factory standards and tests each component for replacement accuracy and fit. The design focuses on correct application matching for Mazda 6 and Kia Rio emissions control service, with contamination protection built into the sensing element assembly.