Closed Loop Fuel Injection System: Notes
The system is controlled electronically by an oxygen sensor that is located in the exhaust pipe ahead of the catalytic converter. The catalytic converter has a metal structure that is coated with a porous layer that contains the catalysts Rhodium and platinum or palladium.
The catalytic converter is very effective within a very narrow range. If the fuel-air mixture is not kept within this range, the levels of one or more gases will undoubtedly exceed the permitted limits. A closed loop fuel injection system is a guaranty that the fuel-air mixture will be correct.
Provided that the closed loop fuel injection system gives an optimal fuel-air mixture ratio, the catalytic converter reduces the nitrous oxides (NOx) and oxidizes the carbon monoxide (CO) and hydrocarbons (HC). The end products are carbon dioxide (CO2), water (H2O) and nitrogen (N2).
In order for the catalytic converter to reduce the emissions, the car must be run on unleaded petrol only. This is because lead destroys the active components of the catalytic converter.