Honda CR-V Catalytic Converters
A catalytic converter is used in the exhaust systems of Honda CR-V engines. The converter collects the gas emissions that are dangerous to the environment and turns them into relatively harmless vapors that can be released into the atmosphere. If you are going to be working on your catalytic converter, here are some things you should know.
What types of catalytic converters does a Honda CR-V use?Honda uses a three-way oxidation-reduction system for vehicles using gasoline as fuel and a diesel oxidation catalyst system for CR-Vs running on diesel. The three-way oxidation system simultaneously changes three chemical structures produced during the combustion process of gasoline once they are sent into the exhaust system. Hydrocarbons, carbon monoxide, and nitrogen oxides are all formed when a gas-powered car is operated. The three-way oxidation breaks down all three chemical structures into nitrogen, oxygen, carbon dioxide, and water - all-natural elements commonly found in the environment. The Honda CR-V diesel engine uses a diesel oxidation catalyst system. The hydrocarbons and carbon monoxide chemical structures are transformed into water and carbon dioxide.
How is a Honda vehicles catalytic converter made?The core of the CR-Vs converter is made by placing ceramic honeycomb-shaped substrates inside the converter and covering it with a thin coating of a precious metal. Ceramic is used as a base material because it can handle the extreme heat of the gases coming from the engine better than metal and other materials. The ceramic is formed into oval-shaped brick-like structures and placed side by side in the converter. The entire unit is covered with a thin metal plate and bolted to the underside of the CR-V.
The unit also comes with a secondary air injection pump (often called a smog pump) and a sensor. The pump is used to send fresh air into the converter to help with the catalytic process, and the sensor monitors how much air the pump needs to send.
Why types of metals are used?Precious metals are used for their ability to act as a catalyst, initiating the chemical reaction to change the gases coming from the engine and changing them into chemical compounds readily found in the environment. This process is done when the intake pipe takes the gases and sends them into the ceramic honeycombs coated with the precious metals. As the gases pass through, the metals excite the chemical structures and cause them to break apart into safer compounds.
For gas engines, the most common coating is made out of a mixture of palladium and rhodium. The palladium and rhodium work together to break down the gases before they exit the exhaust pipes.
Diesel engine catalytic converters work the same way, but use the metals platinum, aluminum oxide, and palladium to serve as catalysts.