Composition of the exhaust manifold catalytic converters

[JFP in PA]

They are a ceramic honey comb which is coated or impregnated with metals such as platinum which fosters the desired chemical reaction to reduce pollutants in the exhaust stream.

[Dave80GTSi]

So the manifold cats are made of ceramic, while the secondary cats further back are metallic-core based?

[JFP in PA]

Originally Posted by Dave80GTSi

So the manifold cats are made of ceramic, while the secondary cats further back are metallic-core based?

No, the are both ceramic with metal coating/impregnating.

Why are you asking?

[Dave80GTSi]

I recently cut open a secondary cat that some guy had tried to gut, apparently using something like a crow bar and a sledge hammer.

These cat cores are made of metal, so that his efforts to break up the core simply bent it all into a metallic lump. Presumably had the core been ceramic, it is brittle enough so to break up into small chunks under such crow bar force.

My original question was out of curiosity, simply to wonder if the manifold cats were also made of the same metallic construction.

Seems to me that a ceramic core would hold up better under the higher heat exposure so close to the engine.

Thanks - DM

[Dave80GTSi]

Originally Posted by Dave80GTSi

I recently cut open a secondary cat that some guy had tried to gut, apparently using something like a crow bar and a sledge hammer.

These cat cores are made of metal, so that his efforts to break up the core simply bent it all into a metallic lump. Presumably had the core been ceramic, it is brittle enough so to break up into small chunks under such crow bar force.

My original question was out of curiosity, simply to wonder if the manifold cats were also made of the same metallic construction.

Seems to me that a ceramic core would hold up better under the higher heat exposure so close to the engine.

Thanks - DM

Now able to answer my own question.

Both the manifold and the secondary cats are identical in construction materials, and both are made of a non-ceramic metallic honeycomb.

So you can't bust a thru hole via brute force, a crowbar, and a sledge hammer. Like someone - not me - tried to do, as shown in the picture which I posted here earlier.

DM