DPF – Diesel Particulate Filter

What is a DPF?

DPF – a diesel particulate filter (FAP from french Filtre À Particules) is a filter located in the exhaust system of diesel (diesel) vehicles. The filter is installed in engines meeting the EURO 4 standard and above. Its purpose is to clean the exhaust from particulate matter (ash and soot). The aforementioned filter is often combined with a catalytic converter.

Diesel particulate filter – its role and construction

The design of the particulate filter is to provide as much spatial area as possible for the previously mentioned soot and ash to settle. Catching all these impurities all the time while driving, the filter accumulates them. This involves all the time reducing its efficiency in terms of exhaust gas flow. When its efficiency level drops to a certain value, the engine control unit (ECU) begins to regenerate the filter. Such autoregeneration consists in injecting fuel into the exhaust system or additional fuel directly into the cylinder. This increases the exhaust temperature and burns off previously accumulated particles.

It is worth mentioning that the interruption of regeneration involving the injection of fuel directly into the cylinder causes fuel to enter the oil sump through the rings along with the engine oil. This results in a significant deterioration of the properties of the engine oil and an increase in its level.

Even if the vehicle performs the filter regeneration properly, the filter still gets clogged over time. This subsequently leads to continuous regeneration and then to filter failure. Replacing the DPF filter involves costly repairs. These costs can be avoided by installing a DPF emulator.

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