Walker 350-341055 Oxygen Sensor - Downstream or Downstream Right

OE Replacement Downstream Oxygen Sensor

Walker OE Replacement oxygen sensor 350-341055 is a direct-fit, heated narrow-band sensor built for specific vehicle applications. It is engineered to provide the ECU with the feedback needed for proper fuel control and emissions monitoring on supported BMW models.

Walker Products has developed this sensor line as an Original Equipment replacement solution for engine management systems, with application-specific fitment, connector design, and signal output. For BMW 330i, X3, and Z4 downstream service, 350-341055 is specified for the correct position and electrical interface.

Key Features

• Heated narrow-band oxygen sensor for downstream use
• Specific-fit design for the listed BMW applications
• 4-wire configuration with 4 terminals
• Female connector with oblong shape
• Threaded mounting with M18 x 1.5 thread size
• Overall length: 850 mm; wiring harness length: 825 mm
• 22 mm wrench size for service access

Detailed Description

This Walker OE Replacement sensor is designed for downstream monitoring on a wide range of BMW vehicles from 2018 through 2025. It supports emissions-system feedback on models including the BMW 230i, 330e, 330i, 430i, 530i, X3, X4, X5, X6, X7, and Z4, along with select Alpina and M Performance applications. The part number 350-341055 is built for specific fitment positions, including downstream and downstream right, so the connector, harness length, and threaded mount align with the original application.

Walker Products states that its engine management and oxygen/air-fuel sensors are developed as OE replacements for many vehicles worldwide. This line is backed by the company’s ISO 9001/TS 16949 manufacturing environment and long-running focus on engine management and fuel system components. This part cross-references Bosch (e.g., 17098) for the same application.

Common Issues This Sensor May Address

• Check engine light or malfunction indicator light related to oxygen sensor performance
• Poor fuel economy caused by inaccurate exhaust feedback
• Elevated exhaust emissions from a degraded downstream sensor
• Fault codes stored in the ECU for the affected sensor circuit
• Rough engine operation when sensor feedback is no longer reliable

Installation Notes and Tips

Before replacement, inspect the sensor wiring harness and connector for heat damage, abrasion, or corrosion. Confirm the downstream position and connector style on the vehicle before installation, and verify the thread size and mounting type match the original sensor location. On BMW applications, clearing stored fault codes after installation is recommended so the ECU can relearn with the new sensor signal.

Quality Assurance

Walker Products has supplied engine management components since 1946 and manufactures this OE Replacement sensor for application-specific fitment and diagnostic feedback. The brand’s ISO 9001/TS 16949 certification supports controlled production standards for this oxygen sensor line.