73 Temperature after catalyst too low - Down stream catalyst temp - physical (Catalyst heating time failed) - P042B Catalyst Temperature Sensor Circuit Range/Performance
Temperature after catalyst too low - Downstream catalyst temp -physical (Catalyst heating time failed) - P042B Catalyst Temperature Sensor Circuit Range/Performance
Hissing noise at expansion valve, Loss of refrigerant.Restriction in refrigerant system.Check receiver-dryer for uniformity of temperature.