Denso 234-4208 Oxygen Sensor - Upstream

Denso 234-4208 Oxygen Sensor for Universal Fit Applications

The Denso 234-4208 oxygen sensor is a heated, universal-fit emission control sensor built to OE standards for accurate replacement and consistent engine feedback. It is designed for upstream use on select Toyota Corolla, Toyota Supra, and Geo Prizm applications, including California exempt coverage where noted.

Key Features

• Heated oxygen sensor for faster operating temperature and stable signal output
• Universal fit design for select upstream applications
• 4-wire configuration for proper sensor circuit operation
• 11.77-inch wiring harness length
• Precision-built to match OE replacement requirements
• Uses Denso’s aluminum oxide trap layer to help protect the ceramic element from silicone and lead contamination

Detailed Description

Denso 234-4208 is part of Denso’s Universal line, which focuses on exact replacement fit and OE-level manufacturing standards. This oxygen sensor is engineered for upstream placement and is listed for 1988 Toyota Corolla, 1989-1991 Toyota Corolla, 1988-1992 Toyota Supra, and 1990-1992 Geo Prizm applications. It is a practical choice when replacing a worn sensor on a Toyota Corolla oxygen sensor application or a Toyota Supra upstream oxygen sensor setup, and it also covers select Geo Prizm fitments. This part cross-references Bosch (e.g., 13519, 15073) for the same application.

What It Helps Address

• Check engine light caused by a failing upstream oxygen sensor
• Rough idle or inconsistent air-fuel feedback
• Reduced fuel economy from inaccurate exhaust readings
• Slow sensor response during closed-loop operation
• Emissions test failures related to sensor performance

Installation Notes and Tips

Verify the connector style, wire count, and upstream location before installation. Confirm the harness length and routing path match the vehicle layout, especially on 1988-1992 Toyota Supra, 1989-1991 Toyota Corolla, and 1990-1992 Geo Prizm applications. Because this is a universal-fit sensor, proper identification of the original sensor configuration is important for correct installation and signal performance.

Quality Assurance

Denso manufactures and tests this oxygen sensor to strict OE standards for consistent fit and function. The sensor’s protective trap layer is designed to help resist contamination that can shorten sensor life and affect engine performance.