Catalyst Efficiency Monitor
WARNING: This page is about a different car, the 1995 Ford Windstar. However, it is still accessible from the selected car via links, so may be relevant.
Catalyst Efficiency DTC is stored in memory, and Malfunction Indicator Light (MIL) is illuminated after catalyst efficiency monitor detects a malfunction during 3 consecutive drive cycles. MIL is turned off after 3 consecutive trips, during which no malfunction is detected that would normally trigger a DTC. DTC is erased from memory after 40 warm-up cycles, during which no malfunction is detected. DTC can also be erased, by using Powertrain Control Module (PCM) reset function on NGS tester.