Question about 2002 Mitsubishi Galant
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.
Possible causes - Catalyst Heater Control harness is open or shorted
- Catalyst Heater Control circuit poor electrical connection
- Faulty Powertrain Control Module
Posted on Oct 20, 2012
Tips for a great answer:
Sep 04, 2018 | Cars & Trucks
Feb 13, 2014 | 2005 Ford Fiesta Zetec
Dec 26, 2013 | Chevrolet Cavalier Cars & Trucks
Jul 17, 2013 | 2006 Toyota Corolla
Jul 20, 2012 | 2002 Mazda 626
Sep 22, 2010 | 2004 Chevrolet Monte Carlo
Jun 30, 2009 | 2000 Ford Contour
255 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: