The purpose of this paper is to show that air pollution caused by traffic is a major problem that engineers and scientists around the world have been struggling with since the invention of the automobile. A major breakthrough in the fight against air pollution was achieved by Eugene Houdry when he invented the catalytic converter in the middle of the 20th century. Stricter and stricter laws and regulations have led car manufacturers to take the necessary measures to reduce exhaust gases caused by internal combustion engines. Due to the incomplete combustion of fuel in the engine, products such as CO, HC, NOx, PM particles, etc. are formed. These pollutants have a negative impact on air quality, the environment and human health. The method that has proven to be the most convenient and effective for solving this problem is the catalytic converter. There are numerous alternative technologies, which in cooperation with the catalytic converter provide even lower emissions of harmful gases, such as improvements in engine design, fuel pretreatment, particle filters, use of alternative fuels, fuel additives, adjustment of the combustion process using lambda probes, exhaust gas recovery, etc. This the paper talks about the history of catalysts, car exhaust emissions and their impact on the environment, reduction of emissions using catalytic converter, types of catalytic converters, their failures and systems that help them achieve quality results in the fight against air pollution.