Walker 350-34998 Oxygen Sensor - Downstream or Upstream

OE Replacement Oxygen Sensor for GM Applications

Walker Products 350-34998 is a heated oxygen sensor built as a specific-fit OE replacement for select Buick, Chevrolet, and GMC vehicles. It is engineered to provide the ECU with the exhaust feedback needed for accurate fuel control and emissions monitoring.

For drivers searching for a downstream oxygen sensor for a 2023-2024 Buick Encore GX, a 2024 Chevrolet Trax, or an upstream oxygen sensor for a 2022-2024 Chevrolet Equinox, this Walker Products part number 350-34998 matches the application-specific requirements of the vehicle.

Key Features

• Heated oxygen sensor for faster operating response
• Specific-fit design for the listed upstream and downstream positions
• 4-wire configuration with 20-gauge wiring
• Threaded mounting with 18.0 mm thread diameter
• Radiused polygon male connector for OE-style connection
• Wiring harness length: 7.87 in.
• Overall length: 12.79 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered as OE replacements for a wide range of vehicles. Part number 350-34998 is built for the specified fitment position so the sensor output aligns with the ECU’s expected diagnostic feedback. That matters on modern vehicles where a failing sensor can trigger fault codes, increase fuel consumption, raise exhaust emissions, or illuminate the malfunction indicator light.

This sensor is listed for applications including Chevrolet Malibu upstream oxygen sensor replacement, Chevrolet Spark downstream oxygen sensor replacement, and GMC Terrain upstream or downstream service depending on model year and position. It is also listed for Buick Encore, Buick Encore GX, Chevrolet Equinox, Chevrolet Trailblazer, Chevrolet Trax, Chevrolet Cruze, Chevrolet Volt, and related GM platforms.

What It Helps Address

• Check engine light related to oxygen sensor performance
• Rough running caused by incorrect exhaust feedback
• Higher fuel consumption from inaccurate air-fuel correction
• Elevated exhaust emissions from a degraded sensor signal
• Fault codes stored in the ECU for upstream or downstream sensor circuits

Installation Notes

Confirm the required position before installation: upstream or downstream. Verify connector shape, thread diameter, harness length, and wire count against the original sensor before replacement. Inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion, since physical damage can shorten service life and affect signal quality.

Fits 2022-2024 Chevrolet Equinox, upstream; 2022-2024 Chevrolet Malibu, upstream; 2023-2024 Buick Encore GX, downstream; 2024 Chevrolet Trax, downstream; and other listed Buick, Chevrolet, and GMC applications.

Quality Assurance

Walker Products has supplied engine management and fuel system components since 1946 and manufactures to Automotive ISO9001/TS 16949 standards. Part number 350-34998 is produced as an OE-style replacement sensor for the listed applications.