I currently have a 2014 5.3 Silverado. I had a magna flow catback system put on it quite a few thousand miles ago so it should be past it’s “break in period” but the only thing I’ve noticed is that it drones louder but the actual sound outside of the cab isn’t all that great. I really don’t want to swap over to a flowmaster or borla since I spent the money for the magna. Any suggestions besides muffler delete?

 

on my 2014 4.3 I replaced the muffler with a flowmaster 40 series and removed the resonator. I love the sound.

 

I'm also curious about the answer to this question