Possible causes

– Faulty Air fuel ratio (A/F) sensor 1 bank 1
– Air fuel ratio (A/F) sensor 1 bank 1 harness is open or shorted
– Air fuel ratio (A/F) sensor 1 bank 1 circuit poor electrical connection
– Inappropriate fuel pressure
– Faulty fuel injectors
– Intake air leaks may be faulty
– Exhaust gas leaks

Tech notes

Replacing the Air fuel ratio (A/F) sensor 1 bank 1 usually takes care of the problem.

For Infiniti models before 2005 see: P0131 Infiniti

When is the code detected?

The Air Fuel Ratio (A/F) signal computed by Engine Control Module (ECM) from the A/F sensor 1 signal is constantly in the range other than approx. 1.5V.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– High Fuel Consumption
– Excessive Smoke from Exhaust

P0131 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