DPF Problem

Happy birthday to all of you guys. I am having dpf problem in my tool. It gives p1457 fault on the computer. Previously, the filter was removed and cleaned a total of 3 times, and the liquid was completed and regenerated from the computer, but my fault continues. My master said that the filter is defective and needs to be replaced. Or it seems to be canceled. If anyone has experienced such a problem before, which routes did you follow? What are your suggestions?

Have you looked at the dpf temperature and pressure sensor. Ultimately, the difference detects whether this filter is working or not with a pressure sensor. Do not let this sensor malfunction.? How many kilometers is the vehicle?