Frequently used to disable immobilizer systems, which is helpful when replacing an ECU with a used unit. DPF/EGR Delete:
on the vehicle when reading or writing files to prevent voltage drops that cause write failures.
Modifying ECU files carries a high risk. If the checksum isn't corrected or the file is corrupted during the "decode" process, you can "brick" the ECU, making the car unable to start.