Integrated Air Fuel Catalyst Monitor
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2011 Mercury Milan, 2011 Mercury Mariner, 2011 Mercury Grand Marquis, 2011 Lincoln Town Car, and 2011 Lincoln Navigator L. However, it is still accessible from the selected car via links, so may be relevant.
The integrated air fuel catalyst monitor is an on board strategy designed to monitor the oxygen storage capacity of the catalyst after a deceleration fuel shut off (DFSO) event. The monitor determines the amount of fuel needed to drive the catalyst to a rich condition when starting from an oxygen saturated, lean condition. The monitor is a measure of how much fuel is required to force the catalyst from a lean to a rich condition. The monitor runs during fuel reactivation following a DFSO event. The monitor completes after a calibrated number of DFSO monitoring events have occurred. The integrated air fuel catalyst monitor is used with a heated oxygen sensor (HO2S) or a universal HO2S.