Iritating noise when accelerating or under load coming from the cat

[Dave2018]

This is something that has been going on for a number of years but has been steadily getting worse. I finally got underneith and started banging around on the exhaust system and believe that I have isolated it to the cat. There is a heat shield on one side of the cat. Can't tell if it's that or something Inside the converter itself.

1. Has anyone else had this noise?

2. Have you been able to stop it short of replacing the cat?

I'm going to put a large hose clamp around the cat and heatshield and crank it down tight. I'll post if that stops it.

 

[Hero6]

Dave, my sons 97 5.2 just similar problem. Cat was rattling, ended up being the insides were moving around, blocking the exhaust flow and causing a loss of power. We gutted the Cat by removing the inside honeycomb material and that fixed the issue, no more rattle, and power back to normal. I also have an 04 Expedition that was doing the same thing, it also included a loss of power, replaced Cat with a new one. Hopefully yours is just the shield rattling, have you noticed a loss of power? Keep us posted.

 

[MADDOG]

I've had heat shield mounting screws fail with the cat rattling on the top of the cat & I've had cats fail and start rattling internally.

When I hear that noise I always start with the heat shield first and go from there.

 

[Dave2018]

You'd think we have entered monsoon season here. I haven't had a dry day available to get under the truck and tie on a big hoseclamp around the cat. I'll post the results when I do. No, the truck seems to have normal power so I dont think its plugged internally.

Thanks for all the suggestions I appreciate it!