## 1 Introduction
The molar ratio CO\({}_{2}\)/CO is significantly higher in the case of catalytic regeneration compared with thermal regeneration [6; 7; 8]. Therefore, diesel particulate filters play an important role in the environmentally friendly operation of diesel-fueled vehicles. The DPF is used in conjunction with an exhaust backpressure monitoring system [9]. Failure to maintain these filters can lead to significant consequences for the diesel vehicle. Namely, blocking the DPF has a significant effect on engine performance with increase in particulate depositions. The most common reasons for DPF failures are [10]:  
1. Frequent short journeys where the engine doesn't reach optimum operating temperature 2. EGR valve problems, such as stuck or fouled EGR components
3. Faulty fuel injectors sending too much fuel to the air/fuel mixture
4. The use of the wrong engine oil--low ash, low sulfur oil must be used on DPF equipped vehicles. 5. Turbo failure with oil dripping into the DPF: oil passes through turbo seals into the exhaust housing and the burnt oily residue enters the DPF, causing excessive dense soot loading. 6. High mileage vehicle that will find regeneration harder As representative damaged type of DPF [11], DPF pinholes are breakages in which 0.1-10 mm holes are generated orthogonal to the flow between channels inside DPF. Moreover, melting failure is a type in which the DPF filter melts due to the high temperature exhaust gas, resulting in the formation of an empty space inside the filter axial direction. Cracking failure occurs in the DPF's circumferential direction and is known to be caused by a temperature gradient generated by the difference in channel blockage inside the filter. If the DPF becomes clogged, the soot generated by the diesel engine is released into the atmosphere in its natural state. When the carrier of DPF is damaged, the filtering performance of the PM is lowered. PM contains inhalation particles (PM\({}_{10}\) and PM\({}_{2.5}\)) small enough to penetrate the chest region of the respiratory tract. In the short term (time, day), asthma deterioration, respiratory symptoms and hospitalization increase, and damage occur, and long-term (month, year) exposure increases the mortality rate from cardiovascular and respiratory diseases and lung cancer. The vulnerable groups with lung or heart disease, as well as the elderly and children, are particularly vulnerable [12]. Therefore, it is vital to manage this system under normal operating conditions. The exhaust differential pressure data provide one among various methods for assessing DPF as a diesel after-treatment device. This can be determined by comparing the collected PM with one of the on-board diagnostics (OBD) data criteria for assessment, which is based on whether the collected PM is regenerated. If there is no pressure gradient, the DPF is damaged. In addition to pressure, temperature is a feasible OBD data point. By applying the principle of forcibly burning soot accumulated during DPF regeneration, it is feasible to examine the present state of the DPF and identify whether it is malfunctioning. The other means is a resistance-type PM sensor that diagnoses the state of the post-treatment device by applying a voltage to the surface electrode of the sensor element and measuring the amount of current flowing between the electrodes to determine the quantity of PM emission. It is available commercially. The microwave approach is utilized to determine the soot (ash) load of a DPF by employing two antennas and the resonant frequency as a signal obtained from the reflection coefficient [13]. Failures of DPFs are most commonly attributed to a single catastrophic event such as uncontrolled DPF regeneration or a single upstream engine component failure. DPFs have been widely used commercially for several years, and field observations indicate that non-event-linked DPF failures also occur [14]. Therefore, the DPF manufacturer would require knowledge of the cause of the DPF failure.