P1139 CHEVROLET HO2S Insufficient Switching Bank 1 Sensor 2

Possible causes

– Faulty HO2S Bank 1 Sensor 2
– HO2S Bank 1 Sensor 2 harness is open or shorted
– HO2S Bank 1 Sensor 2 circuit poor electrical connection

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)