PETROL ENGINES

On Petrol vehicles, primary lambda sensors are required for correct and safe engine operation, these cannot be removed. The secondary Lambda sensors however can be removed safely. The secondary Lambda sensors are located after the vehicles Catalytic convertor and serve the purpose of checking the correct operation of the Catalyst. In high performance applications, owners often wish to remove the restrictive catalyst to aid exhaust gas flow. This unfortunately leaves modern vehicles with an engine management or emissions light on as the vehicle has failed the catalyst check.
 

DIESEL ENGINES

On Diesel vehicles the situation is much different. Whilst they often have primary and secondary lambda sensors, none are required for safe operation of the engine as they serve a different purpose. Diesel engines are typically lean burn engines and Lambda sensors are only used to check if fuelling becomes too rich, to avoid black diesel smoke. As a result, with correct software calibration both the primary and secondary Lambda sensors can be removed from Diesel vehicles. The vehicle can be configured to use other inputs for smoke monitoring, such as manifold pressure sensors or air flow meters alone.