Cars with catalytic converter in the exhaust system

Hyundai cars fitted as standard with a catalytic converter. The presence of catalyst require the use of unleaded petrol. Cars with controlled catalytic converter must also be equipped with a device controlled mixing.

Under controlled mixing device means a system of fuel injection in which the fuel / air ratio can be continuously varied depending on the operating conditions and the oxygen content in the exhaust gases.

Team management unit mixing receives oxygen sensors (lambda probe), which is mounted in front of the catalytic converter or exhaust manifold and blown by the flow of exhaust gases, lambda probe - an electrical sensor that registers the residual oxygen content in the exhaust gases with a corresponding electrical signal . The signal allows us to conclude the working mixture. In fractions of a second lambda probe can provide a corresponding signal to the electronic control unit, at the expense of the working mixture can be continuously adjusted. On the one hand it is necessary, as the constantly changing operating conditions (e.g., full power, idle), on the other hand because an optimum post-combustion occurs in the catalytic converter only if the exhaust gas has a sufficient amount of carbon particles (unburned gasoline).

Thus, to at +300 ... +800 ?� C in the catalyst generally afterburning could occur in the exhaust gases containing a large amount of fuel than necessary for complete combustion in the engine cylinders. In this regard, during operation of a vehicle equipped with an engine with a catalytic converter, the fuel consumption is increased by about 5%. The catalytic converter is located in the engine compartment of the car on the front-silencer. The catalytic converter comprises a ceramic honeycomb block coated with a noble metal catalyst: platinum or rhodium. To mount the sensor to the shock of the ceramic block, flexible, heat-proof wire mesh.

Used catalyst is a so-called three-component catalyst. This means that the converter simultaneous oxidation of carbon monoxide (CO) and hydrocarbons (CH), and reduction of nitrogen oxides (NOx).