2x Up & Downstream Oxygen Sensor For 2014-2017 Subaru Forester WRX 2.0L H4 Turbo Fit for: 2014-2017 Subaru Forester 2.0L H4 Turbocharged 2015-2017 Subaru WRX 2.0L H4 Turbocharged Specifications: OE Numbers: 22690-AB010, 234-4988, 22641-AA650, 234-5178, 22690AB010, 2344988, 22641AA650, 2345178 Product Material: Stainless Steel Color: Black, 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. .
