Who knew...? 2nd cat inside OE muffler

Ok, finally got a chance to open up @MACAWS OE muffler he gave me. I wanted to see how bad it looked in there. Based on others comments you would have thought it was tacked together with bubblegum and bailing wire.... it's quite interesting with three chambers including an additional catalytic converter prior to heading out to the down exit pipe. The rattling people have reported has to be the catalytic honey comb breaking free or apart inside. I sectioned it off so I could play with it a little to see if I could open the air flow a little. Want be hard and I can weld all the panels back on to test. First to go will be the cat or just open up extra perimeter holes around it. Will also add a few extra cross over pipes and maybe do the dual outlet at the bottom. The dual pipes people have done really are just going into the first chamber. This could be cheap fun...
I'll take the pictures 1/2/3 as the gas goes through the muffler. The second picture shows the three 1.5" pipes leading from the first chamber into the second containing the single 3" catalytic opening into the third chamber. The 3rd picture is hard to see but it contains a perforated barrier for some fiberglass matting (removed for the image). It is in this chamber that the exit pipe is welded in (under mesh screen) and then exits back through the 2nd chamber and out. It was this diagonal exit back through the 2nd chamber that was screwing with my head when I tried to figure the flow out. The exit pipe is isolated and sealed as it goes back through the 2nd chamber.

@Orangeman I know some see it as a butt ugly pig but I have yet heard a muffler that I like enough for the money being asked. Until I do I thought it might be fun seeing what could be squeezed out of the OE first. Besides it kind of fits without extra mods. Who knows it might end up sounding better?

Well say I was surprised by the extra cat.

in the 3rd picture can see the high heat spot just past the cat on the mesh screen . Wonder how much cooler tbatuffler would be without the heat generator functioning?

Quote from Canoehead

Are we sure it is a 2nd cat? I'm more inclined to believe it is a spark arrestor. This done due to the fact of the angle of the exhaust exit.

Its appearance is exactly like the cat in the mid -pipe. Good point about the angle the exhaust exits. Regardless it's a freaking huge restrictor in the system.
The discoloration of the mesh screen just past it tells me that it's producing some good conversation heat.
@JDSKY I understand what you are saying. I do know of it and agree it's a very nice system. I'm just playing with a free part and spare time. It's how I figure things out that might be relevant to something else later own. Just a curious person that's all.

OK Franken-Can is back together. Hate stitch welding thin steel. Two passes to insure no pin holes...
Could not get the 2nd cat out (yes I do still believe it is a 2nd Catalytic converter) so I drilled three perimeter 1.5" holes to allow better flow. Also added four 1" holes leading from the 1st chamber over to the 2nd. Should allow far better breathing. Would I do another .... (Nope).... lot of cutting, drilling, and welding. Wife's out of town so nothing really better to do the last two evenings. Best part it's an OE part so remove the current one. Reinstall this one and test. If I hate it no money spent and easy switch back...

Quote from Nemesis1701

I do however have a question, which one component you would think to come loose and cause a rattling sound?
I have returned a stock muffler because of an internal rattling sound.

there are (3) 1.5" through pipes going from the 1st chamber to the second. If the welds broke free on one of these that could have caused it. The muffler I cut open didn't appear to have weak welds. The only other part I can think of would be the 2nd Catalytic converter. Possible it broke up but again the one in this muffler was in there solid. That leaves on other possibility... @Nemesis1701 your SS is spitting unneeded parts out over time...

ok... it's back in and I fired it up... sounds deeper but it's in the garage. Will need to let it cool down a little because my stupid butt forgot to put the new heat shield back on before I cranked it. Hope I don't have to undo those damn springs to install....
Plan to drive it tonight and see how it sounds outside. Feels like it does rev faster but could all be in my head ....

@MACAWS...... either a compliment or a jab..... .....
I think I know what you ment....

FRANKEN-CAN is all settled in. Nice thing about the new heat shield .... you really can't see how ugly he is... ok maybe a little...

Quote from Shatneyman

Right!!!! How come your smiling?

good... I thought I was the only one seeing it...

Well here goes nothing. Taking her out for a spin...