Check the cat on the drivers side. I think you can tap it with a wrench or hammer. You may can hit it with the palm of your hand (cat cold of course!!!!). My dad’s 16 F150 Ecoboost rattles as well but no power lose. I’m going to do that test on it when we change the oil this week.
Have you checked for codes? I wouldn’t floor it again until you get it fixed. If you need to drive it then granny it.
1966 Mustang straight 6 Red and White
2012 V6 MCA Silver
C/S Spoiler, JLT Catch Can, Airaid Modular Intake Tube w/ Ford emblem, AFE Pro-Dry Air Filter, Polyurethane Swaybar Bushings front and rear, LED Interior lights, LED License Plate bulbs, LED Reverse Lights