Quote Originally Posted by Polaraco View Post
With the truck cold, try to beat on the catalytic converters with you hand and see if it rattles. I'm thinking the core may be lose. If you hear a slight clunk, that's probably it. Unless it is something you can't live with, you can leave it for a while. If it get's worse in time, then replace it. Not sure what your muffler design is, but it could eventually partially clog it. If it were a gasser, I would say get it out as there are 2 converters. 04 and newer cats were mandatory. Heavy fines if your caught without it. There's a slim chance of that happening unless you like to smoke.
It's been a while and I feel like a jerk for not updating but it's the cat that is rattling.

Sent from my SM-G955U using Tapatalk