P1124 AUDI Long Term Fuel Trim Adjustment Bank 1 System Too Lean

Possible causes
– Faulty HO2S
– Faulty Mass Air Flow Sensor
– High fuel pressure
– Canister purge solenoid stuck open
– HO2S harness is open or shorted
– HO2S circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)