as we already know the exhaust gases from Cars contain pollutants that aren't healthy for the environment and hence the catalytic converter commonly known as catcon began to be introduced a catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less toxic pollutants by catalyzing a redox reaction it is installed on on every internal combustion engine car be it diesel or gasoline the harmful components released by automobiles are carbon monoxide hydrocarbons nitrogen oxides Etc from their exhaust pipes the catalytic converter is placed or fixed in the exhaust system of the vehicles which is convenient to operate the catalytic converter consists of a special Catalyst it is made of platinum and padium which carries out the chemical reactions pollutants like carbon monoxide convert them chemically to less dangerous pollutants like carbon dioxide catalytic converters are placed as close as possible to the engine because they require a temperature of 400° C to operate effectively they are usually located underneath the car between the engine and Muffler before we jump into working on the catalytic converter let's take a quick look at the history of how it started the history of the catalytic converter dates to the end of the 19th century when some prototypes were developed in France Eugene hudry a French mechanical engineer received a patent for his research to develop catalytic converters for gasoline engines hudry was an expert in catalytic oil refining having invented the catalytic cracking process that all modern refining is based on today when the result results of early studies of smog in Los Angeles were published hudry became concerned about the role of Smoke Stack exhaust and automobile exhaust in air pollution and founded a company called oxy Catalyst he first developed catalytic converters for smoke stacks and later developed for warehouse forklifts that used low-grade unleaded gasoline in the mid 1950s he began research to develop catalytic converters for gasoline engines used on cars and was awarded the United States patent for his work catalytic converters were further developed by a series of Engineers including Carl D keth John J Mooney Antonio elazar and Philip MSA at Engelhard Corporation creating the first production catalytic converter in 1973 to comply with the new exhaust emissions regulations by the US Environmental Protection Agency most gasoline powered vehicles manufactured from 1975 onwards are equipped with catalytic converters there are two types of catalytic converters used in automobiles two-way catalytic converter and three-way catalytic converter the two-way catalytic converter housing consists of a Honeycomb Core from the inside and it is substrate coded with platinum and Palladium Metals these metals react with the engine's exhaust gases and these gases are directed to flow through the substrate which allows the chemical reaction to take place at first it reacts with the carbon monoxide generated by the combustion of gasoline it also reacts with the hydrocarbons formed by unburned Fuel thus the catcon converts these gases into less harmful byproducts which are carbon dioxide and water vapor a two-way or oxidation catalytic converter has two simultaneous tasks oxidation of carbon monoxide to carbon dioxide oxidation of hydrocarbons unburnt and partially burnt fuel to carbon dioxide and water a combustion reaction the process may seem simple in this type of catalytic converter yet there are a few requirements that must be met for the process of oxidation to work seamlessly there should be pure air moving through the exhaust manifold continuously two-way converters operate relatively efficiently with a lean fuel mixture which is ineffective in controlling nitrogen oxides the two-way type only has an oxidation Catalyst therefore it can't effectively oxidize nitrogen which contributes to smog and acid rain when released into the atmosphere as a result the two-way converter was phased out of most gasoline engines in America and Canada after 1981 to make way for the three-way converter which contains rodium to control the emission of nitric oxide and nitrogen dioxide newer gas- powered cars have three-way converters because they're required to meet stricter emission standards and it is the only device that reduces all three pollutants the three-way catalytic converter uses two catalysts namely a reduction Catalyst and an oxidation Catalyst the oxidation catalyst is made of Palladium and platinum whereas the reduction catalyst is of rodium and platinum however both of them come with a ceramic honeycomb substrate the reduction and oxidation catalysts are typically contained in a common housing when the exhaust gas comes into contact with the catalysts chemical reactions occur that result in the conversion of harmful pollutants such as hydrocarbons carbon monoxide and nitrogen oxides into less harmful substances like carbon dioxide water vapor and nitrogen gas the reduction catalyst is particularly effective at reducing nitrogen oxides while the oxidation Catalyst primarily targets hydrocarbons and carbon monoxide as a result of these chemical reactions the exhaust gas exiting the catalytic converter becomes cleaner and contains significantly reduced levels of harmful pollutants this contributes to improved air quality and reduced environmental impact a three-way catalytic converter has three simultaneous tasks reduction of nitrogen oxides to nitrogen and oxygen oxidation of carbon monoxide to carbon dioxide oxidation of unburnt hydrocarbons to carbon dioxide and water these three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stochiometric point that is 14.7 Parts air to one fuel by weight for gasoline the ratio for autog gas or liquefied petroleum gas natural gas and ethanol fuels is each slightly different requiring modified fuel system settings when using those fuels there are two types of systems running in a catalytic converter lean and Rich that means when the system is running lean there is more oxygen than required and when the system is running rich there is more fuel than needed catalytic converters work best when the engine runs with just the right mix of air and fuel which is called stochiometry when the engine runs slightly richer than the ideal balance of air and fuel it starts producing more carbon monoxide and unburnt fuel this happens because there not enough oxygen for complete combustion this makes it harder for the Catalyst in the car's exhaust system to clean up the emissions by converting carbon monoxide and unburnt fuel into less harmful substances in a rich mixture where there is more unburned fuel present because of less oxygen the combustion process tends to be cooler which can reduce nox formation to some extent to keep the Catalyst working efficiently it's important to maintain the air fuel ratio close to the Ideal Balance if it stays too rich or too lean for too long the Catalyst won't be able to do its job [Music] properly when the engine runs with a slightly lean mixture it means there's more air than fuel this excess oxygen in the exhaust gases can increase the production of nitrogen oxides while reducing the efficiency of the catalytic converter in reducing nox however the excess oxygen enhances the conversion of hydrocarbons and carbon monoxide into water and carbon [Music] dioxide in general engines fitted with three-way catalytic converters are equipped with a computerized Clos Loop feedback fuel injection system using one or more oxygen sensors placed in the exhaust system to measure the amount of oxygen present in the exhaust gases this information helps deter whether the air fuel mixture is rich or lean the engine control unit ECU receives signals from the oxygen sensors and adjust the rate of fuel injection into the engine accordingly this system helps three-way catalytic converters work well by maintaining a balance between rich and lean fuel mixtures if the oxygen sensor detects a rich mixture or excess fuel the ECU reduces fuel injection to lean out the mixture conver firstly if the mixture is lean or has excess oxygen the ECU increases fuel injection to enrich the mixture by maintaining an ideal air fuel ratio or oscillating slightly around it the closed loop control system ensures that the catalytic converter operates at its peak efficiency on a modern diesel engine emission systems vary in arrangement depending on the manufacturer and use case but always start with in cylinder emissions reduction the most common form of in cylinder emissions reduction is the exhaust gas recirculation system or EGR EGR works by returning a small portion of an engine's exhaust gas back to the engine's combustion Chambers through the intake manifold where it mixes with fresh air and fuel during the combustion process this means that less oxygen reaches the cylinder less oxygen means a lower combustion temperature this way nitrogen oxide quantities can be reduced by up to 70% as the higher the temperature the more harmful nitrogen oxides are produced in diesel engine cars the most commonly used catalytic converter is the diesel oxidation Catalyst the catalytic converters used on gasoline cars won't work on diesel because the exhaust stream is different and expels a lot more unburned fuel and oxy in the exhaust because diesel all run in a lean the diesel oxidation Catalyst docc works almost identical to gasoline engines it is designed to oxidize carbon monoxide gasphase hydrocarbons and the sof fraction of diesel particulate matter to carbon dioxide and water these converters often operate at 90% efficiency virtually eliminating diesel odor and helping reduce visible particulates these catalysts are ineffective Ive for KNX so nox emissions from diesel engines are controlled by exhaust gas recirculation EGR the diesel particulate filter DPF positioned after the doc Catalyst the DPF acts as a filter trapping and removing particulate matter like dirt and soot from the exhaust gases diesel exhaust contains relatively high levels of particulate matter the do Catalyst removes only 20 to 40% of particulate matter so partic are cleaned up by a diesel particulate filter modern DPF is a walllow ceramic monolithic filter which mainly consists of cordite silicon carbide or aluminum titanate engine exhaust gas is forced to flow through a porous wall to adjacent Outlet channels of the DPF then most suit accumulates on the filter to keep the filter clean the collected soot must be burnt via DPF regeneration the purpose of DPF regener eration is to remove accumulated particulate matter or soot from the filter which can otherwise lead to decreased engine performance and increased emissions if left untreated then the exhaust gases enter the scr Catalyst Housing which contains the scr Catalyst which helps break down harmful emissions the scr catalyst is typically made of materials like titanium dioxide or Vanadium pentoxide this Catalyst facilitates a chemical reaction that reduces harmful nitrogen oxide emissions into harmless nitrogen and water [Music] vapor selective catalytic reduction scr systems have become the preferred method for meeting tier 4 final and euro6 diesel emission standards for heavy trucks and also for cars and Light commercial vehicles these systems are effective at cutting down on harmful emissions like nitrogen oxides particulate matter and hydrocarbons by as much as 95% nearby there's a tank that holds aquous Ura solution which is also referred to as diesel exhaust fluid DF DF is used to reduce KNX the fluid is composed of 32.5% Uria and demineralized water the diesel exhaust fluid is pumped from the tank to an injector located near the scr Catalyst the injector sprays diesel exhaust fluid and an aquous Ura solution into the exhaust stream just before it enters the scr Catalyst this helps further reduce harmful emissions then the treated exhaust gases exit through the tailpipe as def enters the system it evaporates into ammonia and water the ammonia sticks on the scr Catalyst and binds with the nitrogen oxides as they pass over the Catalyst once bound the nitrogen oxides will combine with the ammonia to create a chemical reaction resulting in nitrogen and water water the temperature and noock sensors are installed upstream and downstream of the scr Catalyst to monitor exhaust temperature and KNX concentrations the sensors provide information to an electronic control unit ECU which adjusts the def injection rate to make sure the scr system works efficiently while using diesel exhaust fluid effectively the advantages of catalytic converters mainly include the following catalytic converters reduce 87% of hydrocarbon emissions 85% carbon monoxide and 62% nitrous oxide throughout the expected car life the catalytic converter is an essential device in gas fueled cars if the car generates emissions it requires this converter it reduces harmful emissions from the Cars once a catalytic converter is removed then the horsepower in some cars will be increased as a result we can produce more horsepower without it this converter should work very hard to get similar energy if we remove this it will reduce the burden and you can attain better gas mileage while it's true that removing a catalytic converter can sometimes result in a slight increase in Horsepower it's important to note that doing so is illegal in most regions due to emissions regulations additionally any horsepower gains from removing the catalytic converter may come at the expense of increased emissions and environmental harm the catalytic converter does create some exhaust back pressure which can affect engine performance to a minor extent modern engine management systems are typically capable of compensating for this removing the catalytic converter May indeed reduce the burden on the engine potentially resulting in improved gas mileage overall while removing the catalytic converter May yield small performance gains it is not recommended due to Legal environmental and ethical considerations it's important to comply with emissions regulations and use responsible tuning practices to achieve performance improvements while minimizing environmental [Music] impact the signs of a clogged catalytic converter mainly include the following waning fuel efficiency verify the warning light engine issues less acceleration the emission test will fail engine light will be on a rattling noise within the engine getting fewer miles for each gallon car jerks ahead fuel loss throughout acceleration and the engine will be misfired so that's it for today what do you think about this system share your thoughts in the comments if you found this video helpful then please share it with your friends subscribe to the channel for more 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