Walker 350-34253 Oxygen Sensor - Downstream or Upstream

Walker 350-34253 Oxygen Sensor Overview

Walker Products 350-34253 is a heated oxygen sensor built as a specific-fit OE replacement for select Toyota, Lexus, and related applications. It is engineered to deliver the ECU feedback needed for downstream and upstream emissions monitoring on covered vehicles, including Toyota 4Runner, Tacoma, Land Cruiser, Previa, T100, and Lexus LX450 applications.

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors for exact application fitment, with this part number matched to the required mounting position and connector style for the listed vehicles.

Key Features

• Heated oxygen sensor for emissions and fuel-control feedback
• Specific-fit design for the listed vehicle applications
• 4-wire configuration with 20-gauge wiring
• Radiused polygon male connector for application-specific connection
• Flange mount design with 18.0 mm thread diameter
• Wiring harness length: 19.41 in.; overall length: 22.95 in.
• Walker Products 350-34253 for downstream and upstream positions where listed

Detailed Description

Walker Products 350-34253 is an oxygen sensor designed for direct replacement in select Toyota and Lexus emissions systems. As a heated sensor, it helps provide the ECU with the feedback needed to manage air-fuel control and monitor catalyst efficiency on the specified upstream or downstream locations. This part number is listed for 1993-2000 Toyota and Lexus applications, including downstream Toyota 4Runner, Tacoma, Land Cruiser, Previa, T100, and Lexus LX450 coverage, plus upstream Toyota Previa coverage where specified. For buyers searching for a downstream oxygen sensor for 2000 Toyota Tacoma, a Toyota 4Runner oxygen sensor replacement, or Walker 350-34253 for Lexus LX450, this part is matched to the exact application notes shown in the fitment data.

Walker Products Aftermarket has supplied engine management components since 1946 and manufactures application-specific sensors for the required fitment position and diagnostic feedback. This part cross-references no additional part numbers in the provided data.

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 readings
• Higher exhaust emissions from a failing sensor
• Fault codes stored in the ECU for the affected sensor circuit

Installation Notes and Tips

Confirm the exact year, make, model, emissions package, and sensor position before ordering. This part is listed for both upstream and downstream positions depending on the vehicle, so match the fitment row to your application. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion before installation, since damaged wiring can shorten sensor life and affect readings. Verify the connector shape, thread diameter, and mounting style against the original sensor before replacement.

Quality Assurance

Walker Products manufactures engine management sensors as OE-style replacement components for specific applications and positions. The brand is ISO 9001 / TS 16949 certified, supporting controlled manufacturing and application-focused fitment for emissions control service parts.

Compatible Vehicles

• Fits 2000 Toyota 4Runner, downstream — Oxygen Sensor for California vehicles with ESV regulations.
• Fits 1999 Toyota 4Runner, downstream — Downstream placement for vehicles without California emissions certification.
• Fits 1996-1997 Toyota 4Runner, downstream — Downstream oxygen sensor for vehicle installation.
• Fits 1996-1997 Lexus LX450, downstream — Downstream oxygen sensor for vehicle installation.
• Fits 1996-1997 Toyota Land Cruiser, downstream — Downstream oxygen sensor for vehicle installation.
• Fits 1994-1997 Toyota Previa, upstream — Bank 1 Sensor 1 needs an upstream oxygen sensor.
• Fits 1994-1997 Toyota Previa, downstream — Fits downstream bank 1 sensor 2 on specific vehicle models.
• Fits 1995 Toyota Land Cruiser, downstream — From 1/95; Del 1/95; Downstream.
• Fits 1994 Toyota T100, downstream — Downstream oxygen sensor for vehicle installation.
• Fits 1993 Toyota T100, downstream — Oxygen Sensor for California vehicles with ESV regulations.