A few words should be said about the installed catalyst.
Oxygen sensor inserted into the exhaust system (on injection engine) or in the exhaust manifold (on a carbureted engine). Exhaust gases act on the outer electrode of the sensor. The inner electrode is connected to the atmosphere. Due to certain chemical reactions, the filling of the probe and the different oxygen content in the exhaust gases and the atmosphere, an electrical signal is generated. At temperatures above 300°C, the probe transmits a voltage signal to the control unit. If the voltage is less than 450 mV, the mixture is richer, if the voltage is greater than 450 mV, the mixture is leaner.
To maintain a constant temperature, the probe is heated. The probe heating element is electrically powered and remains energized while the fuel pump is running.
The catalyst is located in the exhaust system in front of the mufflers. Exhaust gases flow through the catalyst and interact with the precious metal inside the catalyst (platinum/rhodium). Under the influence of oxidation, harmful substances are converted into a harmless gas. The chemical reaction starts at a temperature of 250°C.
As you know, a car with a catalyst should only be refueled with unleaded gasoline (normal or super, i.e. AI95 or AI98).
Do not park a vehicle with a hot catalyst over dry grass or the like, as the underbody may ignite and cause a fire.