Except for the 45TFSI version, all other versions of the Audi A4L are equipped with a particulate filter. Audi is one of the oldest German car manufacturers with exquisite craftsmanship in automobile production. A particulate filter is a ceramic filter installed in the exhaust system of diesel engines, which captures particulate emissions before they enter the atmosphere. It can reduce the soot produced by diesel engines by more than 90%, and the captured particulate emissions are subsequently burned off during vehicle operation. Working principle of the particulate filter: The diesel particulate filter is coated with metals such as platinum, rhodium, and palladium. The black smoke containing carbon particles emitted by the diesel engine enters the exhaust particulate filter through a specialized pipe. After passing through the densely arranged bag-type filters inside, the carbon particles are adsorbed onto the filter made of metal fiber felt. When the adsorption of particles reaches a certain level, the burner at the end automatically ignites, burning off the carbon particles adsorbed on it and converting them into harmless carbon dioxide. To check whether the Audi A4L is equipped with a particulate filter, you can use the following 3 methods: Check the and to see if there is a particulate filter function. Additionally, you can carefully check the fault codes in the manual to see if there is a "particulate filter" warning light indicator; Check the label above the oil filler cap. If the oil cap clearly indicates 0W-20 grade oil, it means it is equipped with a particulate filter; Check whether there is a cylindrical section on the exhaust pipe behind the three-way catalytic converter. If there is, that is the particulate filter.
