Denso 234-4055 Oxygen Sensor - Downstream or Upstream

Denso OE Style Oxygen Sensor 234-4055

Denso 234-4055 is an OE Style heated oxygen sensor built for exact replacement and first-time fit. It is engineered for specific applications on Toyota 4Runner, Pickup, and Van models, with coverage for upstream and downstream positions where listed.

The OE Style line focuses on direct-fit replacement parts that match original equipment dimensions and connector requirements. For Toyota 4Runner, Toyota Pickup, and Toyota Van applications, this sensor supports accurate exhaust feedback and consistent drivability when the original sensor is worn or slow to respond.

Key Features

• Heated oxygen sensor for faster operating temperature and stable signal output
• Specific-fit design for direct replacement on listed Toyota applications
• 4-wire configuration
• 20.87-inch wiring harness length
• OE Style construction for factory-like fit and connector alignment
• Built with Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination

Detailed Description

Denso 234-4055 is manufactured and tested to OE standards for replacement use on select Toyota vehicles. It is listed for 1990-1991 Toyota 4Runner upstream, 1989-1991 Toyota Pickup upstream, 1989-1991 Toyota Pickup downstream, 1989-1990 Toyota Pickup upstream with 22-inch sensor, and 1988-1989 Toyota Van upstream. This part cross-references Bosch 13401 and NTK 24111 for the same application.

As an OE Style oxygen sensor, this unit is built to match the original sensor’s fit and electrical layout, helping maintain proper exhaust monitoring on Toyota 4Runner, Toyota Pickup, and Toyota Van platforms. The heated design supports quicker sensor operation after startup, while the protective trap layer helps extend service life in demanding exhaust environments.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Slow or inaccurate air-fuel feedback
• Reduced fuel economy caused by a worn sensor
• Rough idle or hesitation tied to exhaust sensor signal issues
• Failed emissions testing caused by sensor degradation

Installation Notes and Tips

Verify the sensor position before ordering, since this part is listed for both upstream and downstream locations on select Toyota Pickup applications. Confirm connector style, wire count, and harness length against the original sensor before installation. Use the vehicle’s exact year, model, and emissions configuration to match the listed fitment, including California and 22-inch sensor notes where applicable.

Quality Assurance

Denso manufactures this oxygen sensor to strict OE standards and tests each component for replacement accuracy and fit. The OE Style design is intended to deliver the correct part and the correct fit for the listed Toyota applications.