Walker 350-34405 Oxygen Sensor - Downstream or Upstream

Walker 350-34405 Oxygen Sensor for Toyota Applications

Walker Products 350-34405 is a heated oxygen sensor built as an OE-style replacement for specific Toyota vehicles. It is engineered for the correct application and mounting position so the ECU receives the feedback it expects for emissions and fuel control.

For Toyota 4Runner, Toyota T100, and Toyota Pickup applications, this sensor supports downstream and upstream positions across select 1993-2000 models, including California-emissions and non-California configurations.

Key Features

• Heated oxygen sensor design for faster operating temperature
• Specific fit application for the listed Toyota vehicles
• 4-wire configuration with 22-gauge wiring
• 6.61 in. wiring harness length
• Radiused polygon male connector for direct replacement use
• 18.0 mm thread diameter with flange mount design
• Overall length: 10.16 in.

Detailed Description

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors developed as replacement parts for original equipment applications. Part number 350-34405 is built for the correct sensor location and vehicle-specific calibration needs, helping maintain proper ECU feedback on the covered Toyota 4Runner, Toyota T100, and Toyota Pickup models. This part number 350-34405 is intended for select upstream and downstream positions, including B1S1 and B1S2 applications where listed.

This Walker oxygen sensor is a practical choice when servicing Toyota emissions systems that rely on accurate exhaust monitoring. If the sensor signal is degraded, the vehicle may run poorly, use more fuel, or trigger a malfunction indicator light. The sensor, connector, and wiring should also be inspected for damage during diagnosis.

This part cross-references no listed aftermarket part numbers in the provided data.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Rough running caused by incorrect exhaust feedback
• Increased fuel consumption from inaccurate air-fuel correction
• Elevated exhaust emissions from a failing sensor
• Fault codes stored in the ECU for sensor-related issues

Installation Notes and Tips

Confirm the exact year, model, emissions package, and sensor position before ordering. This Walker 350-34405 uses a specific-fit design, so matching the connector style, thread diameter, and mounting type is important for proper installation. Inspect the harness and connector for heat damage, corrosion, or abrasion before replacing the sensor.

For Toyota 4Runner, Toyota T100, and Toyota Pickup service, verify whether the vehicle calls for upstream or downstream placement and whether California-emissions or non-California fitment applies.

Quality Assurance

Walker Products states that its engine management sensors are developed as OE replacement parts and manufactured under Automotive ISO9001/TS 16949 certification standards. The brand has supplied engine management and fuel system components since 1946.