Fixing rattling cat converter
 

My cat started rattling, dang. And at 2700 rpm right where i drive most the time. Anyone have a pic of what these look like inside, are they the honey comb type? I was thinking of drilling some small holes and pushing some steel rods up in there to put pressure on the broken sections and then weld them in place, to try and compress it together again so it does not rattle around. Would be a quick experiment in fixing the dang thing.

Any ideas, input or pics of the internals of this thing? It's a 86' stock cat.

Info: ******** Parts Catalog

Here's a recent thread on that: http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/555137-gutted-s2-cat.html

Are you sure the rattle is coming from inside the cat? I found my rattle to be the upper heat shield on the cat had come loose.

just replaced my cat, but still got a rattle at almost exactly 3250 (indicated) RPMs. Stays as long as I can at that Rev... disappears immediately after or before...

If it's the cat you guys don't fool around with it replace it ,I had a cat disintegrate on me with my 83-944,lucky it happen at low speed around 30 mph.What it did was all the SHT inside when througt the muffler ruin a perfect muffler plus blew two intake gaskets.So got mad & didn't buy an OE one, this guy had a brand new SS one, beleive me or not it's for a Honda. I had to mod thing a small bite but made it to fit perfectly been on the car many years now & still working strong.Has a nice sound to. http://forums.pelicanparts.com/uploa...1280532808.jpg
http://forums.pelicanparts.com/uploa...1280532834.gif

I tried pressing on the heat shields when the rattle was happening to see if it was the shields, did not seem to help. I actually want the cat working because it really makes a diffrence in the fumes. I hate driving behind a non cat car smells terrible. My 911 is a carbs only car and wow, so stinky, kinda feel sorry for the guys behind me on hard drives.... Ill see if my method works and also start looking for a good used one

Hit it with a rubber hammer and see if it rattles, if so replace it.
You really can't FIX a converter once the substrate has broken up.

Good advice 968rz, ill do that.

check your o2 sensor and make sure its tight , I had the same problem replaced the cat and still rattled turn out sensor was loose about a 1/2 a turn !