Walker 350-34438 Oxygen Sensor - Downstream Left or Downstream Right

Walker Oxygen Sensor for Lexus Downstream Left Applications

Walker Products 350-34438 is a heated oxygen sensor built as a specific-fit OE replacement for select Lexus vehicles. It is engineered to deliver the diagnostic feedback the ECU expects, helping maintain proper fuel control and emissions monitoring on downstream left applications.

Key Features

• Heated oxygen sensor for downstream left placement
• Specific-fit design for direct application matching
• 4-wire configuration with 20-gauge wiring
• Threaded mounting with 18.0 mm thread diameter
• Radiused polygon male connector for vehicle-specific connection
• Wiring harness length: 41.85 in.; overall length: 45.39 in.
• Walker Products Aftermarket line for engine management and oxygen/air-fuel sensor replacement

Detailed Description

Walker Products 350-34438 is designed for Lexus models that use a downstream left oxygen sensor, including Lexus GS350, IS250, IS300, IS350, RC300, and RC350 applications across the 2007-2018 model years listed below. This part number is built for the specified fitment position so the ECU receives the correct sensor feedback for emissions and drivability monitoring. Walker Products has focused on engine management and oxygen/air-fuel sensor replacement since 1946, and this sensor reflects that OE-style application-specific approach.

This part cross-references no listed interchange numbers for the same application.

What It Helps Address

• Check engine light related to downstream oxygen sensor faults
• Poor fuel economy caused by inaccurate exhaust feedback
• Elevated exhaust emissions from a failing sensor
• Rough engine operation tied to incorrect ECU sensor input
• Stored fault codes in the ECU for affected sensor circuits

Installation Notes and Fitment

• Fits 2018 Lexus IS300, downstream left.
• Fits 2018 Lexus IS350, downstream left.
• Fits 2018 Lexus RC300, downstream left.
• Fits 2018 Lexus RC350, downstream left.
• Fits 2016-2017 Lexus IS300, downstream left.
• Fits 2014-2017 Lexus IS350, downstream left.
• Fits 2016-2017 Lexus RC300, downstream left.
• Fits 2015-2017 Lexus RC350, downstream left.
• Fits 2015 Lexus GS350, downstream left.
• Fits 2013 Lexus GS350, downstream left.
• Fits 2007-2011 Lexus GS350, downstream left.
• Fits 2015 Lexus IS250, downstream left.
• Fits 2014 Lexus GS350, downstream left.
• Fits 2014 Lexus IS250, downstream right.
• Fits 2014 Lexus IS250, downstream left.

Confirm the connector shape, thread size, and sensor position before installation. Inspect the sensor wiring harness and connector for physical damage, since damaged wiring can shorten sensor life and affect ECU feedback.

Quality Assurance

Walker Products manufactures engine management sensors as OE replacement parts for specific applications and positions. The brand is ISO 9001/TS 16949 certified, supporting consistent production and application-specific fitment for Lexus oxygen sensor replacement needs.