4Pcs Up & Downstream Oxygen Sensors Fit 2018 2019 2020 Ford F-150 5.0L 234-5731 Fit for: 2018-2020 Ford F-150 5.0L Specifications: OE Numbers: 234-5731, 234-5732, 234-8050 Product Material: Stainless Steel Product Color: As Shown in the Picture Installation Position: Upstream, Downstream Functions: 1. The Upstream oxygen sensor is used to Monitor Raw Exhaust Gas to Adjust Air-fuel Ratio in Real-time, i.e., it is used to Detect Whether the Exhaust Gas Exceeds the Standard. 2. The Downstream oxygen sensor is mainly used to Detect Whether the Three-way Catalytic Converter Works Normally. .
