Walker 350-34312 Oxygen Sensor

Walker 350-34312 Oxygen Sensor Overview

Walker Products 350-34312 is a heated oxygen sensor built as a direct-fit OE-style replacement for specific Lexus and Toyota applications. It is engineered to deliver the diagnostic feedback the ECU expects, helping maintain proper air-fuel control and emissions performance.

Walker Products Aftermarket focuses on application-specific engine management sensors, and this oxygen sensor follows that approach with the correct fitment position, threaded mounting, and connector configuration for the listed vehicles.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for listed Lexus GS300 and Toyota Highlander/RAV4 applications
• Threaded mounting type with 18.0 mm thread diameter
• 4-wire design with 20-gauge wiring
• Radiused polygon male connector for proper vehicle-side connection
• Wiring harness length: 29.06 in.; overall length: 32.6 in.
• Walker Products part number 350-34312 for direct identification

Detailed Description

Walker Products 350-34312 oxygen sensor is designed for vehicles that rely on accurate exhaust oxygen feedback to manage fuel delivery and emissions. It is a specific-fit sensor for 1998-2005 Lexus GS300 upstream applications, plus select 2001-2004 Toyota Highlander and 2001-2003 Toyota RAV4 downstream positions. For shoppers searching for a Lexus GS300 upstream oxygen sensor or a Toyota Highlander downstream oxygen sensor, this part number provides a direct replacement path.

As part of the Walker Products Aftermarket line, this sensor is built around application-specific fitment so the ECU receives the expected signal from the correct mounting position. The design supports vehicles that store fault codes when an oxygen sensor or related circuit begins to fail, making accurate replacement important for drivability and emissions control. Part number 350-34312 is also a useful reference when comparing Walker 350-34312 against other OE-style oxygen sensor listings.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Poor engine operation caused by incorrect exhaust feedback
• Increased fuel consumption from inaccurate air-fuel control
• Elevated exhaust emissions from a failing heated oxygen sensor
• Fault codes tied to the sensor, wiring harness, or connector

Installation Notes

• Verify the exact position before installation: upstream, downstream, downstream front, or downstream rear.
• Confirm connector shape, wire count, and thread diameter match the original sensor.
• Inspect the sensor wiring harness and connector for physical damage before replacement.
• Check the exhaust bung threads and mounting surface for contamination or wear.
• Use the vehicle’s service information to confirm the correct bank and sensor location.

Quality Assurance

Walker Products states that its engine management and oxygen/air-fuel sensors are developed as OE replacement parts for worldwide vehicle applications. The company is ISO 9001/TS 16949 certified and has supplied engine management components since 1946.

Compatible With: 1998-2005 Lexus GS300 upstream; 2001-2004 Toyota Highlander downstream; 2001-2003 Toyota Highlander downstream; 2001-2003 Toyota RAV4 downstream rear and downstream front. Walker 350-34312 is a direct-fit oxygen sensor for these listed applications.