Subaru Oxygen Sensor 22641-AA590 / 234-9108 Precise Replacement

Subaru oxygen sensor OEM 22641-AA590/234-9108; installed on exhaust manifold or pipe; monitors exhaust oxygen and feeds ECU to adjust air-fuel ratio; ensures combustion efficiency and emissions compliance. Fits 2010–2014 2.5L models (Forester, Outback, Liberty), installation difficulty moderate; 30–45 minutes; use specialized socket to avoid thread damage. If check engine light on, idle unstable, or fuel economy rises, sensor may be failing.