Subaru OEM Rear 02 Sensor (03-07 WRX, 04-07 STi)

Item # 22690AA520

This Subaru OEM sensor is the Rear 02 Sensor.  This sensor needs to be working properly at all times.  If you're getting any of the P0139-P0159 codes its likely your Rear sensor is bad.

*This sensor is only for the manual transmission model