Denso 234-4978 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor 234-4978

The Denso 234-4978 is a heated downstream oxygen sensor built as a specific-fit OE-style replacement for select Honda Fit applications. It is engineered for direct replacement performance, accurate exhaust feedback, and a first-time fit on compatible vehicles.

Key Features

• Heated oxygen sensor for downstream exhaust monitoring
• Specific-fit design for direct replacement on select Honda Fit models
• 25.59-inch wiring harness length for proper routing
• 4-wire configuration for the listed application
• OE Style construction for factory-style fit and function
• Built with Denso’s aluminum oxide trap layer to help protect the sensing element from silicone and lead contamination

Product Details

Denso OE Style sensors are manufactured and tested to OE standards, with precision-built components that match the original application. This Denso oxygen sensor 234-4978 is designed for downstream placement on 2015-2020 Honda Fit models, including Fits 2015-2019 Honda Fit, downstream and Fits 2020 Honda Fit, downstream. It supports accurate exhaust gas monitoring, which is important for maintaining proper fuel control and emissions system operation. This part cross-references Honda 365325R0004 for the same application.

For shoppers searching for a downstream oxygen sensor for Honda Fit 2015-2020, or a direct-fit replacement oxygen sensor for Honda Fit OE style applications, this part number 234-4978 matches the listed vehicle coverage and connector/wiring requirements.

Common Issues This Part May Address

• Check engine light related to oxygen sensor performance
• Incorrect air-fuel ratio feedback from a worn downstream sensor
• Reduced fuel economy caused by inaccurate exhaust readings
• Emissions test failure tied to sensor response issues
• Slow or inconsistent sensor output from age or contamination

Installation Notes and Tips

Verify the downstream sensor location, connector style, wire count, and harness length before installation. Compare the original sensor to the Denso 234-4978 to confirm the specific-fit application for your Honda Fit. Inspect the exhaust threads and wiring path during replacement to help ensure proper routing and secure installation.

Quality Assurance

Denso manufactures this OE Style oxygen sensor to strict original-equipment standards and tests each component for fit and performance consistency. The design includes an aluminum oxide trap layer intended to help protect the ceramic sensing element from contamination, supporting long-term sensor reliability in the listed application.