Monitored Emission Control Systems
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. 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 exhaust gas recirculation (EGR). The OBD II regulations require monitoring of the following:
- Comprehensive component monitoring-Emission related inputs and outputs
- The EGR system
- Misfire monitoring
For the specific DTCs required for each system, refer to Inspection/Maintenance (I/M) System DTC Table .