Denso 234-4921 Oxygen Sensor - Downstream

Denso OE Style Oxygen Sensor for Corolla

This Denso OE Style oxygen sensor is a direct-fit, heated downstream replacement for select Toyota Corolla models. Built for exact replacement and first-time fit, it supports accurate exhaust feedback for consistent engine management on 2014-2019 Toyota Corolla applications.

Denso part number 234-4921 is engineered to OE standards and uses a specific-fit design with a threaded mounting style, 4-wire male connector, and 31.57-inch wiring harness length. The heated sensor design helps the engine control system reach operating temperature efficiently, while the aluminum oxide trap layer helps protect the sensing element from silicone and lead contamination.

Key Features

• Direct-fit Denso OE Style oxygen sensor
• Fits 2014-2019 Toyota Corolla, downstream
• Heated sensor design for faster operating readiness
• Specific fit with 4-wire male connector
• Threaded mounting type with 0.708-inch thread diameter
• 31.57-inch wiring harness length for proper routing
• OE-style replacement for accurate sensor placement

Product Details

Denso 234-4921 is built as an OE-style oxygen sensor for the downstream position on the Toyota Corolla. It is designed to match factory fitment requirements and provide the correct connector, thread size, and harness length for the listed application. This part cross-references NTK 24808 for the same application.

The Denso OE Style line focuses on precision-built replacement parts that align with original equipment specifications. For Corolla owners searching for a downstream oxygen sensor for 2014-2019 Toyota Corolla, Denso 234-4921 offers a direct replacement path without requiring fitment guesswork.

Common Issues This Sensor Can Address

• Check engine light related to downstream oxygen sensor faults
• Incorrect exhaust oxygen readings reported to the engine control system
• Reduced fuel economy caused by a failing sensor signal
• Slow sensor response from an aging heated oxygen sensor
• Fitment problems from a non-specific replacement part

Installation Notes and Tips

Confirm the vehicle is a 2014-2019 Toyota Corolla with the downstream sensor location before ordering Denso 234-4921. Match the connector style, wire count, thread diameter, and harness length to the original sensor before installation. Because this is a threaded, specific-fit oxygen sensor, proper removal and installation practices help prevent damage to the exhaust bung and wiring.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for consistent replacement quality. The sensor design includes an aluminum oxide trap layer intended to help protect the ceramic element from silicone and lead contamination, supporting long-term sensor durability and stable engine performance.