Possible causes
– Faulty Oxygen Sensor
– Vacuum leak affecting bank 1 only
– Fuel injector problem bank 1
– Check for cylinder misfire on bank 1
– Engine mechanical condition
– Vacuum leak affecting bank 1 only
– Fuel injector problem bank 1
– Check for cylinder misfire on bank 1
– Engine mechanical condition
Tech description
Though the Oxygen (O2) sensor, the Engine Control Module (ECM) has detected a lean system, which means that there is either not enough fuel or and excessive amount of air in the system. Start by checking for vacuum leaks.
When is the obd code mean?
The Engine Control Module (ECM) detected bank 1 oxygen (O2) at its lean limit
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1131 FORD OBD Code Description