Particulate filter (engines with a working volume of 1.9 l) (Opel Astra H)

The soot filter is designed to clean exhaust gases from soot. Over time, when the vehicle is in use, soot particles accumulate in the filter. Using a differential control sensor, the exhaust gas pressure is measured before and after the filter. At a certain pressure difference, the engine management system automatically regenerates (cleans) the filter - while the vehicle is moving, by changing the amount of injected fuel, the temperature of the exhaust gases passing through the soot filter increases to 600°C, which leads to the combustion of soot particles. If the filter is heavily contaminated, the engine preheating indicator lamp lights up on the instrument panel (see Chapter "Controls and operating techniques"). The regeneration process can last up to 15 minutes and is usually not felt by the driver.

(Text copied from an online resource OpelBook.ru)