P1100 AUDI HO2S12 Sensor Circuit Voltage Too Low Air Leak

Possible causes

– Faulty HO2S12 Sensor
– Exhaust leak near HO2S12 Sensor
– HO2S12 Sensor harness is open or shorted
– HO2S12 Sensor circuit poor electrical connection

Symptoms

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