4x Up & Downstream Oxygen Sensor Fit for: 2017-2020 Ford F-150 V6 3.5L Turbo Specifications: OE Numbers: 234-5174, 234-5713, 234-8017, 234-4961 Product Material: Stainless Steel Product Color: Silver 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. Packaging Weight: 468 g .
