After you get the Ultra Jump, go to the place where you travel to Fahr Outpost and go back outside. Fall off the platform, then do an Ultra Jump on the red X to grab the sewage pipe near the ceiling. Then, go through the large hole in the wall and you will be back in the Fahr Outpost pipe room. Let go of the pipe and you will land on a hidden platform near a treasure chest. The chest contains an FP plus P badge.