How Does the Particulate Filter Work in Diesel Cars?

The particulate filter (abbreviated DPF) is a filter integrated into the catalytic converter that traps carbon particles generated during combustion when exhaust gas passes at a certain temperature. The DPF thus suppresses particle and smoke emissions, protecting the environment. This component is commonly installed in diesel engines to comply with consumption and emission regulations….

With the particulate filter, it is possible to capture nearly 99% of the polluting particles in a filter, and this, through heat (at high revolutions) and the addition of an additive (depending on the manufacturer) or a post-injection, both in the chamber and at the inlet, regenerates by destroying the particles.

When to change the particulate filter?

A diesel-powered vehicle, with an installed and operational filter, will not emit visible smoke from its exhaust pipe.

Depending on the use of the vehicle, this filter tends to clog due to not performing regenerations correctly. Efficient driving will prevent the need to change the particulate filter.

Most failures related to particulate filters can be diagnosed before the situation worsens, and the most costly and problematic failure. If you drive a diesel and notice abnormal operation, such as the exhaust pipe often emitting dark and dense smoke, that the engine speed frequently rises during driving, or that regeneration periods occur frequently, it is better to go to the workshop and consult it.

Something as simple as an engine diagnosis can reveal if the particulate filter is not functioning correctly, and even workshops are equipped with systems that can effectively regenerate the engine to extend its life or, in the worst case, quote a particulate filter change.

Workshops can detect the malfunction of the particulate filter before the failure worsens, and this malfunction can be anticipated by noting the abnormal operation of our car.

As problematic as the particulate filter may be, in many cases because cars equipped with it should have more reliable regeneration systems, and should be focused on a use that generally is not the one they receive (many kilometers, and generally on the road), you should not disable it.

This is relevant because indeed the ITV (Vehicle Technical Inspections) are monitoring the emptying of particulate filters and that some workshops are practicing it. And you should know that, as we stated at the beginning, the particulate filter was designed to prevent serious pollution and health problems. Essentially, those who remove the particulate filter only succeed in further polluting the air in our cities and harming the health of others.

Not to mention that we are facing an illegal act, as the removal violates the pollution and emissions specifications for which the car was homologated, and for some time this practice has been monitored and controlled in the Technical Vehicle Inspections, so that the ITV can identify and inspect cars with the particulate filter removed to prevent their circulation.