A catalytic converter is a very simple device using the basic redox reactions in chemistry to help reduce the pollutants car makers. It converts around 98% of the harmful fumes produced by a car engine into less harmful gases. It is composed of a metal housing that has a ceramic honeycomb -type interior with insulating layers. This honeycomb interior has thin wall channels that are coated with a wash coat of aluminum oxide. Th is is very porous and increases the surface area, which allows for more reactions to take place. This is where the precious metals arelocated. These metals include platinum, rhodium, and palladium No mo re than 4-9 grams of these precious metals are used in a single converter. The converter utilizes simple oxidation and reduction reactions to convert toxic fumes into gases that are not nearly as harmful to the environment. Recall that oxidation is the loss of electrons and that reduction is the gaining of electrons. These precious metals listed earlier pro mote the transfer of electrons and in turn the conversion of toxic fumes.