Subaru OEM Rear Oxygen Sensor Subaru STi 2008-2021 | 22690AA850 CM Each pump individually tested to

Each pump individually tested to flow minimum of 400LPH (100gph) @ 40 PSI

Make sure the area is clean and free from any product similar to Armor All

Part #: 571101

NOTE: Injectors are only sold in sets of 6 and ECU tuning is required

while significantly improving engine output

Subaru OEM Rear Oxygen Sensor Subaru STi 2008-2021 | 22690AA850 CM Each pump individually tested toFor your: Subaru STi 2008 2021 Rear O2 Sensor The rear oxygen sensor is used to sense oxygen concentration in the exhaust gas. If the air fuel ratio is leaner than the stoichiometric ratio in the mixture (i. e., excessive amount of air), the exhaust gas contains more oxygen. To the contrary, if the fuel ratio is richer than the stoichiometric ratio, the exhaust gas contains almost no oxygen. Detecting the oxygen concentration in exhaust gas using the