P1284 Mitsubishi Air Fuel Ratio Sensor 1 Rich Shift Monitoring Bank 2

Possible causes

– Faulty Air fuel ratio (A/F) sensor 1 Bank 1
– Faulty Air fuel ratio (A/F) sensor 1 heater Bank 1
– Fuel pressure
– Faulty Fuel injector
– Faulty Air Flow Meter

Tech description

What about the obd code?

The A/F signal computed by ECM from the A/F sensor 1 signal is shifted to the rich side for a specified period.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Possible rough engine idle

P1284 Mitsubishi 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