P2240 Subaru Oxygen (O2) Sensor Positive Current Control Circuit / Open (Bank 2 – Sensor 1)

Possible causes

– Air/Fuel Ratio Sensor Bank 2 harness is open or shorted
– Air/Fuel Ratio Sensor Bank 2 circuit poor electrical connection
– Faulty Air/Fuel Ratio Sensor Bank 2
– Inappropriate fuel pressure
– Faulty fuel injectors
– Intake air leaks may be faulty
– Exhaust gas leaks

Tech description

What about the obd code?

If the IPB 2 terminal voltage is out of a specified range, the PCM detects a malfunction and stores a DTC.

Symptoms

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

P2240 Subaru Description

The front air/fuel ratio (A/F) sensor (bank 2, sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. The front A/F sensor transmits output voltage to the powertrain control module (PCM). The PCM controls fuel injection duration by comparing the target air/fuel ratio with the front A/F sensor signal. The sensor includes the VS cell, the pump cell, the atmospheric reference cavity, the diffusion layer, and the heater, and it enables overall feedback control.