Walker 350-34251 Oxygen Sensor - Upstream

Walker Oxygen Sensor for Honda Civic

Walker Products 350-34251 is a specific-fit heated oxygen sensor engineered as an OE-style replacement for select Honda Civic applications. It is built for upstream placement and is intended to provide the ECU with the feedback needed for proper fuel control and emissions monitoring.

For 2001-2005 Honda Civic models, this upstream oxygen sensor supports accurate air-fuel feedback at Bank 1 Sensor 1. The Walker Products Aftermarket line focuses on application-specific engine management components, and this part number is matched to the required fitment position for the vehicle.

Key Features

• Part number: 350-34251
• Heated oxygen sensor design
• Specific fit for select Honda Civic applications
• Upstream mounting position
• 4-wire configuration with 20-gauge wiring
• Male connector with radiused polygon shape
• Threaded mount with 18.0 mm thread diameter
• Overall length: 14.88 in; wiring harness length: 11.34 in

Detailed Description

Walker Products 350-34251 is an emission control sensor designed for vehicles that require an upstream oxygen sensor in the Honda Civic exhaust system. As a heated sensor, it helps the ECU monitor exhaust oxygen content more quickly after startup, supporting closed-loop fuel management and emissions control. The specific-fit design, connector style, and threaded mounting dimensions are matched to the application for proper installation and signal feedback.

Walker Products Aftermarket develops engine management and oxygen/air-fuel sensors as OE replacement parts for worldwide vehicle coverage. This part number is built for the correct application and position, making it a direct choice for 2001-2005 Honda Civic upstream oxygen sensor service. The 350-34251 is also relevant when diagnosing poor fuel economy, elevated emissions, drivability concerns, or a malfunction indicator light tied to oxygen sensor performance.

What It Helps Address

• Check engine light related to upstream oxygen sensor faults
• Poor fuel economy caused by incorrect air-fuel feedback
• Rough engine operation from inaccurate exhaust readings
• Increased exhaust emissions from sensor degradation
• ECU fault codes tied to Bank 1 Sensor 1 performance

Installation Notes and Tips

Verify the connector shape, wire count, thread diameter, and upstream position before installation. Inspect the sensor wiring harness and connector for heat damage, corrosion, or physical wear, since damaged wiring can shorten sensor life and affect signal quality. Confirm the vehicle uses the Bank 1 Sensor 1 upstream location before ordering or replacing the part.

Fits 2001-2005 Honda Civic, upstream. Fits 2001-2005 Honda Civic, front oxygen sensor location. This part cross-references no additional part numbers provided in the source data.

Quality Assurance

Walker Products has supplied engine management and fuel system components since 1946 and operates with Automotive ISO9001/TS 16949 certification. The 350-34251 is manufactured as an application-specific replacement to support the diagnostic feedback expected by the ECU in the listed Honda Civic fitment.