P0159 KIA HO2S21 Circuit Slow Response

Possible causes – Faulty Rear Heated Oxygen Sensor Bank 2– Rear Heated Oxygen Sensor Bank 2 harness is open or shorted– Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection– Inappropriate fuel pressure– Faulty fuel injectors– Intake air leaks may be faulty– Exhaust gas leaks Tech description Replacing the O2 Sensor 2 usually takes…