Subaru Oxygen Sensor 234-9109 22641-AA610 DOX-0623 Direct Replacement OEM Part

For 2.5L Subaru Legacy, Outback, and Forester (2005-2009), oxygen sensors with model numbers 234-9109/22641-AA610/DOX-0623 directly replace the original parts. The sensor monitors exhaust oxygen content and feeds the ECU with air-fuel ratio signals to ensure fuel efficiency and emission control. OEM numbers: 234-9109, 22641-AA610, DOX-0623 for stock cross-checks. Installation difficulty: medium; use a dedicated socket tool and ensure threads are clean.