Yeah. Gotta remove it. Was still difficult to get out without cutting the pipe. Once you disconnect the flange between the cat & dpf you should be able to wiggle it out. Be careful though. When i took mine off it was under a load and it popped off. Pretty sure it nearly broke my hand.
2011 Silverado 2500hd 6.6 Duramax
2006 Silverado 1500 5.3L