Monitored Emission Control Systems
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
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 secondary air injection (AIR) system or Exhaust Gas Recirculation (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 DTCS . 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.