Monitored Emission Control Systems

The OBD-II System monitors all emission control systems that are on-board. Not all vehicles have a full complement of emission control systems. For example, a vehicle may not be equipped with AIR or EGR. The OBD-II regulations require monitoring of the following:

• Air Conditioning System
• Catalytic converter efficiency
• Comprehensive component monitoring - Emission related inputs and outputs
• Evaporative Emissions (EVAP) System
• Exhaust Gas Recirculation (EGR) System
• Fuel Delivery System
• Heated catalyst monitoring
• Misfire monitoring
• Oxygen Sensor System (O2S or HO2S)
• Oxygen Sensor Heater System (HO2S Heater)
• Secondary Air Injection (AIR) System

For the specific DTCs required for each system, refer to INSPECTION/MAINTENANCE SYSTEM DTC TABLE  . Systems such as fuel delivery, misfire, and comprehensive components may not be listed in a system status list. These tests run continuously on some vehicles and may not require an indicator.