Anyone recommend a High Temp goop to help seal Y-Pipe / Cat juncture?

[eightynine4x4]

Ok thanks everyone for all the input.
I jumped the gun before I got response here and totally immersed the juncture in Permatex 2000 degree putty. I believe it’s silicone based which possibly allows a little subtle flex, MAYBE avoiding cracks right away. I could be wrong about it being silicone. Anyways, I let it sit for 48 hrs instead of 24, and did a test sending lightly compressed air up the tailpipe and found I had missed a couple small spots. Basically 33% of the whole perimeter of the gasket had some leaks before adding this goop, then after the first round it had maybe 5%-10% leakage of perimeter. So I added more to those spots and will let it sit for as long as I can again, maybe another 48 hrs, and will do another air test. From what I have gleaned, the issue isn’t weather it will hold up to air pressure but instead it’s about temperature causing deterioration. The layers I created are super thick so we’ll see how that goes.
I’m not expecting this to work perfectly but it could very well be an improvement that performs better than just leaving it as is. If I’m lucky it’ll last until the spring or summer when I can more comfortably attempt to do a proper repair. As for that, i like that idea of chopping the Y pipe just prior to the cat, taking it to a friend who welds (got a buddy), and having them create a new real flange based on old one, then creating a juncture to attach that to Y pipe cut point. I guess a clamp situation could work there? Would be concerned about expansion and heat and what not.

 

[PetroleumJunkie412]

>catalytic converter
>silicone

ngmi.

 

[eightynine4x4]

>catalytic converter
>silicone

ngmi.

I could be wrong. Doesn’t spec silicone anywhere in product info I found. But it does say on package that it’s meant for Cats, and for 2000 F. Whatever that means, who knows! We’ll find out soon!

 

[eightynine4x4]

Also am wondering if there is such a thing as a high temp flexible sheet, like similar to basic aluminum foil in function but a different metal and a lot more robust obviously, that could perhaps be wrapped around the segment to enclose it and then sealed on all edges with a couple sturdy layers of high temp exhaust tape. I'd be concerned about it filling up like a balloon while driving but if the exhaust pressure isn't super high then it might work. Maybe i'll ask NASA haha, they probably have a solution!

 

[Eddo Rogue]

+1 on the rtv red or copper. If you look beyond the local big box parts stores there's some cool specialty stuff out there. Body shop supply stores usually have cool stuff.