Installed the Magnaflow straight thru muffler but left cat on. Doing so deleted the hanger midway from cat to front of muffler, now when starting or turning truck off at times the cat will shake just enough to hit the heatshield a little causing a thumping sound, but not every time. Have bent the heatshield up a little bit but still does it occasionally. Affraid to bent shield up much more affraid it may transfer heat to floorboard. Anyone else have this problem and what did you do. ?? Am also starting another cat delete thread.