Exhaust emission control systems

To prevent pollution of the atmosphere by products of incomplete combustion and evaporation, to ensure the acceleration of the car and save fuel, several devices have been installed to reduce toxicity.

These devices include:

• Electronic ignition distribution system (EST)
• Electronic ignition control system (ESC)
• Exhaust gas recirculation system (EGR)
• Evaporative Emission Reduction System (EECS)
• Forced crankcase ventilation system (PCV)
• torque converter (TSS)
• Catalyst
• Thermostatic air filter
• Air conditioning control system

All these systems are connected, directly or indirectly, to the computer command control system (SSS or SZ).

The sections in this chapter include general descriptions, checks, element replacement operations for each of the above systems.

Before drawing a conclusion about the malfunction of the toxicity reduction system, carefully check the power and ignition systems. Some emissions control devices require special tools, equipment, and skills to test. If you find inspection and maintenance too complicated, or if the related work is beyond your ability, contact an auto repair shop.

This, however, does not mean that the maintenance and repair of the emission reduction system is something particularly difficult. You can easily and quickly perform numerous verification operations and most (if not all) regular maintenance operations using normal hand tools and adjustment devices. Note. The most common cause of problems with the emission control system is a loose or broken vacuum hose or a lack of electrical contact, so always check hose and wire connections first.


Pay special attention to all special warnings in this chapter. It should be noted that illustrations of various systems may not exactly match the system installed on your vehicle due to ongoing modifications made by the manufacturer.

Information plate for emission control systems (VECI) located in the engine compartment (see illustration). This plate includes important system specifications, ignition adjustment operations, and a diagram of the location of vacuum hoses and various components of emission control systems. When servicing the engine or systems, always refer to the VECI plate that is attached to your vehicle.

Note. On models equipped with a Delco Loc II audio system, the audio system interlock system must be disabled before any operation is performed to disconnect the battery.