Hi Exhaust manifold to Cat down pipe flange on my 1999 e150 4.2l is leaking white smoke when I seafoam.

Donut Gasket?

What do you guys use?

I probably over tightened it by now ( i didn't know that expanded the pipe) It leaks and I have no idea what to use to fix it.

 

is it loud and rattly sounding when u drive? i took mine to a local shop they knocked the bolts out, while using a torch, they they appeared to thread a big bolt into it and tightened it up. sounds alot better i needed other work on the exhaust done so i had them do it.