The main systems installed on vehicles and described in this manual include:
- Contactless ignition system
- Air intake system
- Coasting lean system
- Deceleration control system
- Intake air temperature control system
- Positive Crankcase Ventilation (PCV)
The coasting economy indicator system, although not strictly emission related, shares a control unit with the coasting system and is therefore included in this Section.
Chapters in this Section include general descriptions, verification procedures (where possible) and procedures for replacing components (where it is equipped), for each of the systems from the list above.
Before assuming that the emission control system is malfunctioning, thoroughly check the fuel and ignition systems. In some cases, special tools and equipment, as well as specialized training, are required to accurately diagnose the cause of a rough running or hard starting engine. If inspection and maintenance become too difficult, or if these procedures are beyond the capabilities of a home mechanic, consult your dealer's service department. This does not necessarily mean, however, that emission control systems are particularly difficult to maintain and repair. You will be able to do most things quickly and easily (if not all) from inspections and regular home maintenance, general adjustment methods and hand tools.
Note: The most common cause of emissions system failure is a loose or broken vacuum hose or wiring connection. Therefore, always check the hose and electrical connections first.
Pay particular attention to any special precautions outlined in this chapter. It should be noted that the illustrations of various systems may not accurately identify the system installed in your vehicle due to changes made by the manufacturer during production or from year to year.