Walker 350-34252 Oxygen Sensor - Upstream

Walker 350-34252 Oxygen Sensor for Toyota

Walker Products 350-34252 is a specific-fit heated oxygen sensor engineered as an OE-style replacement for select Toyota applications. It is built for upstream placement and provides the ECU with the feedback needed for proper fuel control and emissions monitoring.

Key Features

• Heated oxygen sensor for upstream engine management feedback
• Specific-fit design for the correct application and mounting position
• 4-wire configuration with 20-gauge wiring harness
• Radiused polygon male connector for vehicle-specific connection
• 18.0 mm thread diameter and flange mount design
• Overall length: 13.9 in.; wiring harness length: 10.35 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors developed as OE replacement parts for a wide range of vehicles. The 350-34252 is designed for upstream use on Toyota MR2 and Toyota Celica models, where accurate exhaust oxygen feedback helps the ECU manage air-fuel ratio and emissions performance. This part number is a direct-fit solution for the specified application and position, making it a practical choice for Toyota MR2 upstream oxygen sensor replacement and Toyota Celica front oxygen sensor service.

Fits 1991-1995 Toyota MR2, upstream. Fits 1990-1993 Toyota Celica, upstream. This part number, Walker 350-34252, is listed for the upstream position only and should be matched to the vehicle’s connector, mounting style, and sensor location before installation.

Common Issues This Sensor May Address

• Check engine light related to oxygen sensor performance
• Poor fuel economy caused by inaccurate exhaust feedback
• Rough running or inconsistent air-fuel control
• Increased exhaust emissions from a failing upstream sensor
• Stored ECU fault codes tied to the affected sensor circuit

Installation Notes

Confirm the upstream location, connector shape, thread diameter, and flange mount style before ordering. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life and affect signal quality. For Toyota MR2 and Toyota Celica applications, verify the exact engine and sensor position against the vehicle’s diagnostic information before replacement.

Quality Assurance

Walker Products has supplied engine management components since 1946 and operates with Automotive ISO9001/TS 16949 certification. The 350-34252 is manufactured for the specified application and position to deliver the diagnostic feedback expected by the ECU. Walker 350-34252 is an OE-style replacement oxygen sensor for Toyota MR2 and Toyota Celica upstream service.