General information
To prevent air pollution due to incomplete combustion or evaporation of fuel and to maintain good performance and fuel economy, these vehicles employ several emission control systems. Not all of these systems are installed on all models, but they include:
- Catalytic converter
- Evaporative emission control system (EVAP)
- Crankcase ventilation system (PCV)
- Electronic engine management system
The sections in this Chapter include general descriptions and testing procedures within the capabilities of a home workshop, as well as component replacement procedures (where possible) for all the systems listed above.
Before assuming a problem with the emission control system, thoroughly inspect the fuel and ignition systems. Diagnosing some emission control systems requires special tools, equipment, and training. If inspection and maintenance become too difficult or if the procedure is beyond your capabilities, consult your dealer or other qualified professional.
The most common cause of emission control system problems is a leaking vacuum hose and loose wire, so always check the hose and wire connections first.
This does not mean, however, that the emission control system is particularly difficult to maintain and repair. You can quickly and easily perform many checks and perform most periodic home maintenance with common appliances and hand tools.
Pay close attention to any special precautions given in this Chapter. It should be noted that the illustrations of the various systems may not exactly match the systems installed in your vehicle, as the manufacturer makes changes during the manufacturing process.