Exhaust system
As part of a refurbishment, each section of the exhaust system can be replaced individually.
Exhaust emission control system
Petrol models
Attention! Only unleaded petrol must be used in the power systems of all petrol models!
The principle of operation of the engine management system is designed in such a way as to get the maximum return from the engine with minimal fuel consumption and the content of toxic components in the exhaust gases. The system of trapping fuel vapors prevents the latter from entering the fuel tank into the atmosphere. An exhaust gas recirculation system has also been installed.
Controlled crankcase ventilation system (PCV)
To eliminate leakage of unburned hydrocarbons into the atmosphere, the engine is completely sealed. Gases and oil vapors formed in the crankcase enter the intake manifold through a strainer and burn in the cylinders along with the fuel.
Gases are removed from the crankcase due to the pressure difference in the crankcase and inlet pipeline (pressure in the crankcase is higher).
Exhaust gas recirculation system (EGR)
The exhaust gas recirculation system helps to reduce the amount of NO X in the exhaust gases. To do this, a small part of the exhaust gases is fed into the intake manifold through a special valve. The valve of the recirculation system is controlled by the control unit.
Evaporative Emission System (EVAP)
To reduce the emission of unburned hydrocarbons into the atmosphere, a fuel recovery system is installed on all gasoline models. The filler neck of the fuel tank is hermetically sealed with a lid, a carbon adsorber is installed under the fuel tank. It collects fuel vapors that form in the tank while the car is parked and is stored there until the filter purge begins at the signal of the control unit. Then fuel vapors begin to flow through the valve (s) purge into the intake manifold, where they are mixed with the working mixture and then burned in the usual way in the combustion chambers.
To ensure normal operation of the engine at idle and during warm-up, the control unit keeps the valve closed. This prevents unburned fuel from entering the converter (mixture is too rich at high idle). After the engine warms up, the valve begins to open and close, supplying fuel vapor to the intake tract.
Catalytic converter and lambda probes
To reduce the amount of harmful emissions into the atmosphere on all gasoline models, a three-function catalytic converter is integrated into the exhaust system. The fuel injection control system has feedback, which includes an oxygen sensor. This sensor, installed in the exhaust system, constantly informs the control unit about the composition of the exhaust gases. Depending on the received data, the control unit corrects the quality of the mixture supplied to the combustion chambers and, thus, optimizes the combustion of the fuel.
A heating element is built into the lambda probe, which is switched on by the control unit through a special relay. The working surface of the lambda probe is sensitive to changes in the oxygen content in gases. Depending on the oxygen concentration, the sensor sends signals of different voltages. If the mixture is too rich - the oxygen content in the exhaust gases is very low, the sensor gives low voltage signals. The voltage increases as the mixture becomes leaner and the oxygen content of the gases increases. The converter works most efficiently with the optimal composition of the combustible mixture (14.7 parts of air to 1 part of fuel). When the oxygen concentration in the exhaust gases changes near the optimum value, a voltage jump of the sensor occurs. This jump is the starting point for the control unit when adjusting the quality of the mixture.
Two sensors are installed: one - before, and the second - after the assembly of the catalytic converter. This achieves a more accurate monitoring of the composition of the exhaust gases.
Diesel models
The principles of operation of the diesel engine control system are based on the same requirements as for gasoline units. To further reduce the toxicity of gases, several auxiliary systems are installed on the car. The crankcase ventilation system reduces gas leakage to the atmosphere from the engine lubrication system. The catalytic converter reduces the toxicity of exhaust gases. An exhaust gas recirculation system was installed.
Controlled crankcase ventilation system (PCV)
To eliminate leakage of unburned hydrocarbons into the atmosphere, the engine is completely sealed. Gases and oil vapors formed in the crankcase are passed through a strainer, sent to the intake manifold and burned in the cylinders during the normal operation of the engine
The removal of crankcase gases is carried out due to the pressure difference in the crankcase and inlet pipeline.
Catalytic converter
To reduce the amount of harmful emissions into the atmosphere on all diesel models, a catalytic converter is integrated into the exhaust system. It neutralizes most of the gaseous hydrocarbons, carbon monoxide (SO) and other toxic impurities contained in the combustion products of the air-fuel mixture.
Exhaust gas recirculation system (EGR)
All diesel models are also equipped with an exhaust gas recirculation system, the main task of which is to reduce the percentage of nitrogen oxides in the combustion products of the engine (NOX). In order to accomplish the task, a small part of the exhaust gases from the exhaust system tract is redirected through a special valve to the intake pipeline (see also Section General information). The functioning of the EGR valve is controlled by the control unit.