P0439 Mitsubishi Catalyst Heater Control Circuit Bank 2
Possible causes
– Catalyst Temperature Sensor harness is open or shorted
– Catalyst Temperature Sensor circuit poor electrical connection
– Faulty Catalyst Temperature Sensor
– Catalyst Temperature Sensor circuit poor electrical connection
– Faulty Catalyst Temperature Sensor
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0439 Mitsubishi Description
The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor).
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.
Mitsubishi Vehicle:Mitsubishi Aspire,Mitsubishi Airtrek,Mitsubishi Adventure,Mitsubishi Galant,Mitsubishi Tredia,Mitsubishi Strada,Mitsubishi RVR,Mitsubishi Pajero,Mitsubishi Outlander,Mitsubishi Montero Sport,Mitsubishi Mirage,Mitsubishi Libero,Mitsubishi Legnum,Mitsubishi Lancer,Mitsubishi i Miev,Mitsubishi GTO,Mitsubishi FTO,Mitsubishi Eterna,Mitsubishi eK,Mitsubishi Eclipse,Mitsubishi Diamante,Mitsubishi Delica,Mitsubishi Cordia,Mitsubishi Chariot,Mitsubishi Challenger,Mitsubishi Carisma,Mitsubishi Eclipse,Mitsubishi Endeavor,Mitsubishi Galant,Mitsubishi Lancer,Mitsubishi Outlander,Mitsubishi Raider,