Walker 350-34579 Oxygen Sensor - Upstream

Walker 350-34579 Oxygen Sensor for Toyota Corolla and Geo Prizm

Walker Products 350-34579 is a heated oxygen sensor built as a specific-fit OE-style replacement for select California-emissions vehicles. It is engineered for upstream placement and provides the ECU with the feedback needed to monitor air-fuel control on the affected application.

Key Features

• Heated oxygen sensor for upstream installation
• Specific fit for the listed vehicle applications
• 4-wire design with 20-gauge wiring
• Radiused polygon male connector for application-specific connection
• 18.0 mm thread diameter with flange mount design
• Wiring harness length: 7.4
• Overall length: 10.94

Application Details

This Walker Products Aftermarket sensor line is developed as an OE replacement for engine management systems that rely on accurate oxygen sensor input. Part number 350-34579 is intended for upstream use on 1989-1991 Toyota Corolla and 1990-1992 Geo Prizm California-ESV vehicles. If the original sensor is aging or damaged, the ECU may log fault codes and the vehicle may run rich or lean, increasing emissions and fuel use.

Fits 1989-1991 Toyota Corolla, upstream. Fits 1990-1992 Geo Prizm, upstream.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough running or hesitation from inaccurate sensor readings
• Elevated exhaust emissions on California-emissions vehicles
• Stored ECU fault codes tied to the upstream sensor circuit

Installation Notes

Verify the connector shape, thread diameter, mounting style, and upstream position before installation. Inspect the sensor wiring harness and connector for heat damage, corrosion, or abrasion, since physical damage can shorten service life and affect signal quality. Confirm the vehicle is a California-ESV application before ordering.

Quality Assurance

Walker Products has supplied engine management components since 1946 and operates under Automotive ISO9001/TS 16949 quality systems. Part number 350-34579 is manufactured for the specified application and fitment position to deliver the diagnostic feedback expected by the ECU.