Is there supposed to be a gasket between the exhaust manifold and cats on a 2001 4.0?

[JSpike]

Hello everyone, I'm replacing rear manifold. On 2001 tj 4.0 has factory manifolds and cats. Manifold was cracked and leaking between manifold and cat.my question is there supposed to be a gasket between manifold and cat or is it a compression fitting ??? Was leaking bad and could not tighten flange nuts, crack was# 6 exhaust pipe, which is pretty standard place to happen I hear.

 

[Oldguy]

my 2.5 didnt have a gasket, just cone shaped and tighten well. I did put copper seal in there. dont know if it help though

 

[williambmac]

no exhaust gasket is used between the manifold and the cat.

 

[williambmac]

I have seen people over tighten the bolts and bend the flanges. This usually results in a leak.

 

[JSpike]

Thanks for info ! Didn't look like there was a gasket, front manifold did not leak, could not see the crack in manifold till I removed intake manifold ! The nuts and bolts on flange could not be tightened because of rounded off and rusted, had to cut off ! Looked at scan tool data, bank 1 normal, bank 2 wacko . thanks again !!!