Catalyst Efficiency Monitor

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.