Denso 234-3051 Oxygen Sensor - Upstream

Denso OE Style Oxygen Sensor for Toyota Supra

Denso 234-3051 is an OE Style heated oxygen sensor built for precise replacement and consistent signal performance. It is a specific-fit sensor for the upstream position on 1987-1990 Toyota Supra applications, with a 3-wire design and a 19.69-inch wiring harness length for a direct-fit installation.

For Toyota Supra owners searching for an upstream oxygen sensor replacement, Denso 234-3051 provides the OE-style fit and sensor configuration needed for accurate exhaust feedback and stable engine management.

Key Features

• OE Style replacement for factory-style fit and function
• Heated oxygen sensor design for faster operating readiness
• Specific fit for the upstream position
• 3-wire configuration
• 19.69-inch wiring harness length
• Built and tested to OE standards for replacement accuracy
• Includes Denso aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination

Detailed Product Overview

Denso 234-3051 is engineered as a direct replacement oxygen sensor for 1987-1990 Toyota Supra upstream applications. The OE Style design supports exact fitment, which helps reduce installation issues and keeps the sensor positioned correctly in the exhaust stream. This part number is also referenced by Toyota 8946519145 and 8946519345, along with cross-reference numbers such as Bosch 13909 and NTK 24079 for the same application.

Denso’s OE-focused construction is intended to maintain accurate exhaust oxygen feedback, which is important for fuel control and drivability. The protective aluminum oxide trap layer adds durability by helping shield the sensing element from contamination that can shorten sensor life.

What This Oxygen Sensor Helps Address

• Check engine light related to upstream oxygen sensor faults
• Rough idle or inconsistent air-fuel feedback
• Reduced fuel economy caused by inaccurate exhaust readings
• Slow sensor response during closed-loop operation
• Emissions issues tied to a worn or contaminated sensor

Installation Notes and Tips

Compatible With 1987-1990 Toyota Supra, upstream. Verify connector style, harness routing, and exhaust location before installation. Because this is a specific-fit heated sensor, match the wire count and harness length to the original part for proper routing and secure placement. Denso 234-3051 is designed for direct replacement use in the upstream position on the listed Toyota Supra applications.

Quality Assurance

Denso manufactures and tests this sensor to OE standards for replacement accuracy and first-time fit. The OE Style line is built to deliver the correct part and fit for the application, with contamination protection built into the sensing element design.