As I recall, PS3 saves are encrypted, but if you somehow manage to decrypt it, then "maybe". I haven't tried it. It won't work if the structure is different or uses a different endianness. I suspect you're editing a different file from what you think you're editing. The best way to make sure you're editing the file you think is to make a manual save in the game, sort the save directory by modified timestamp, and pick the most recently modified file. The numbers on the ends of the filenames do not correspond with which save slot they occupy in the game; that is all determined by a separate, directory file that I never figured out how to read.