Possible causes
– Air Fuel Ratio (A/F) Sensor Bank 2 Sensor 1
– Air Fuel Ratio (A/F) Sensor Bank 2 Sensor 1 harness is open or shorted
– Air Fuel Ratio (A/F) Sensor Bank 2 Sensor 1 circuit poor electrical connection
– Fuel pressure
– Fuel injector
– Intake air leaks
– Air Fuel Ratio (A/F) Sensor Bank 2 Sensor 1 harness is open or shorted
– Air Fuel Ratio (A/F) Sensor Bank 2 Sensor 1 circuit poor electrical connection
– Fuel pressure
– Fuel injector
– Intake air leaks
Tech notes
If the P2A03 code is set after a sensor is replaced, check for exhaust leaks and perform the mixture ratio self-learning procedure.
When is the code detected?
The output voltage computed by ECM from the A/F sensor 1 signal is shifted to the lean side for a specified period.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P2A03 INFINITI Description
The Air Fuel Ratio (A/F) sensor is a planar dual-cell limit current sensor. The sensor element of the A/F sensor is the combination of a Nernst concentration cell (sensor cell) with an oxygen-pump cell, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement