I've had an exhaust rattle for a while. I thought I fixed it a couple weeks ago by riveting the heatshield above the cat back on because it was loose. For whatever reason, the rattle went away for a day. Then it came back sounding exactly the same. I figured a rivet popped out. I got under it today with the revit gun, but they were in tact. So I did some banging around and found that the heat shield on the cat itself has come loose. I wrapped the loose end with aluminum tape and some bailing wire. It stopped rattling, but I know it'* not a permanent fix. If I use some JB weld on it, will it hold?

Oh yeah. I believe JB handles up to 500*. I used it to fix my crack on my EGR tube, and it hasn't bothered it one bit. It says on the blister pack to not use it on exhaust systems.

It'* only good to 600* IIRC......

So I don't think it'll last too long.....

Use a big hose clamp

A BIG one.

How hot do you think a cat gets?

Well, if you are using it on the shield above the cat, the JB should be fine. I am actually gonna put some on my shield since it is nearly completely broken off.

This is the shield that is attached to the cat.

Ahh ok, I wouldn't use it then, but I bet cats get quite hot since there is some restriction in it, therefore making more heat than what is coming out of the engine.

Cat externals usually run about 400* on idle... For me anyways...