Hyundai vehicles are equipped with a catalytic converter as standard. The presence of a catalytic converter requires the mandatory use of unleaded gasoline. Vehicles with a controlled catalytic converter must, in addition, be equipped with a controlled mixture formation device.
A controlled mixture formation device is understood to mean a fuel injection system in which the fuel/air ratio can constantly change depending on operating conditions and the oxygen content of the exhaust gases.
The mixing device receives control commands from the oxygen concentration sensor (lambda probe), which is installed in front of the catalytic converter or in the exhaust manifold and is blown by the exhaust gas flow, the lambda probe is an electrical sensor that registers the residual oxygen content in the exhaust gases and issues an appropriate electrical signal. The value of the signal makes it possible to draw a conclusion about the composition of the working mixture. In a fraction of a second, the lambda probe can issue a corresponding signal to the electronic control unit, due to this, the composition of the working mixture can be constantly adjusted. On the one hand, this is necessary, since operating conditions are constantly changing (e.g. full throttle, idle), on the other hand, because optimal afterburning occurs in the catalytic converter only if there is a sufficient amount of carbon particles in the exhaust gases (unburned gasoline).
Thus, in order for afterburning to occur in the catalytic converter at a temperature of +300... +800°C, the exhaust gases must contain more fuel than is required for complete combustion in the engine cylinders. In this regard, when operating a car equipped with an engine with a catalytic converter, fuel consumption increases by about 5%. The catalytic converter is located in the engine compartment of the car in place of the front muffler. The catalytic converter consists of a ceramic honeycomb block coated with a noble catalyst metal: platinum or rhodium. An elastic, heat-resistant wire mesh is used to attach the shock-sensitive ceramic block.
The catalytic converter used is a so-called 3-way catalyst. This means that carbon monoxide is simultaneously oxidized in the converter (SO) and hydrocarbons (CH), as well as a decrease in the content of nitrogen oxides (NOx).