How Does The Lambda Sond System And Catalytic Converter On My Two Series Volvo Work?

The Lambda Sond, or oxygen sensor, system is designed to ensure that fuel air mix is optimally set at all times in order to reduce exhaust emissions and improve fuel consumption.

Instead of sensing the air going in, the Lambda Sond system monitors oxygen levels in the exhaust gases leaving the engine. The oxygen sensor sends its findings to an electronic unit, which then, if necessary, resets the fuel injectors. This constant monitoring and re-setting off the fuel injectors adjusts the air-fuel mix to ensure the best possible environment for combustion. This in turn reduces the three major pollutants in exhaust gases, namely hydro-carbons, carbon monoxide and nitrous gases, in the three-way catalytic converter situated in the exhaust pipe system.

The catalytic converter is an in-line exhaust gas scrubber that is designed to clean the gases before they exit the exhaust system via the tail pipe. It does this by passing the exhaust gases through a series of ceramic elements. The walls of these ceramic layers are plated with a thin layer of platinum-rhodium that invoke a chemical reaction, the effect of which is much reduced levels of the major pollutants.