Walker 350-34055 Oxygen Sensor - Downstream Front

Walker 350-34055 Oxygen Sensor for Toyota Sienna

Walker Products 350-34055 is a heated oxygen sensor built as a specific-fit OE-style replacement for the downstream front position on select Toyota Sienna models. It is engineered to provide the ECU with the feedback needed for proper fuel control and emissions monitoring.

Key Features

• Specific-fit oxygen sensor for the downstream front location
• Heated sensor design for faster operating response
• 4-wire configuration with 22-gauge wiring
• 9.37 in. wiring harness length and 12.91 in. overall length
• 18.0 mm thread diameter with flange mount design
• Radiused polygon male connector for application-specific fitment

Fitment and Application

Compatible with 2001-2003 Toyota Sienna, downstream front. This Walker Products Aftermarket oxygen sensor, part number 350-34055, is built for the exact position required by the vehicle’s emissions system. It is a direct-fit option for Toyota Sienna models that need a downstream front oxygen sensor replacement.

Walker Products Engine Management and Oxygen/Air-Fuel sensors are developed as OE replacement parts for many vehicles worldwide. The Walker Products Aftermarket line focuses on application-specific fitment, correct connector style, and the diagnostic feedback expected by the ECU. Part number 350-34055 follows that approach for the Toyota Sienna platform.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Poor fuel economy caused by inaccurate exhaust feedback
• Elevated exhaust emissions from a failing sensor
• Rough engine operation tied to sensor signal issues
• Stored ECU fault codes for the affected sensor circuit

Installation Notes

Verify the downstream front location before installation and inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion. Confirm thread size, connector shape, and harness length match the original unit on the vehicle. If the original sensor has failed due to wiring or connector damage, correct that issue before installing the replacement.

Quality Assurance

Walker Products is an automotive ISO 9001/TS 16949 certified company with long-standing experience in engine management and fuel system components. Part number 350-34055 is manufactured for specific application fitment and diagnostic system feedback requirements.