CAT/mani fitting question

[Henry]

fitted a new sealing ring/kit to the manifold/CAT joint on my car yesterday and it's still blowing.

the CAT's original; i noticed that the sealing faces at either end are quite badly pitted and am wondering if they're not sealing for that reason.

does this seem a resonable assumption and has anyone had issues like this before?

thanks

 

[Mark One]

not quite sure what to suggest. That join is normally pretty good. Are you sure it's blowing from the mani/CAT join?

Get the spring loaded bolts loose and wiggle it round a bit to get it seated better? then retighten evenly on both sides.
Wouldnt really recommend exhaust paste it that join as it's designed for a little movement, but as a last resort maybe

 

[Henry]

thanks - likewise, thinking paste isn't the best at a joint like that.

the springs are both fully compressed and the CAT's a reasonable fit over the ring as far as i can see/feel. there's clean metal (of varying thickness) around the inside of the CAT bellmouth, but quite a lot of pitting at the outside.

i would consider taking the system off so that i can try realigning the CAT over the ring but it's also blowing from the CAT->system joint, despite having fitted a new gasket (face of the flange is also pitted there).

 

[davebem]

Dont use any kind of paste between the cat/manifold, you dont want that going through the cat.

As above id try and re-align. While its loose put some paste on the gasket between the cat and the system. Ive done this as mine was blowing when i bought my sports cat and new gasket. I sealed it with some silicone gasket stuff from halfords.

 

[Henry]

just re-visited this - thanks for the replies. that's what i think i'm going to do; use some sort of paste at the cat/system joint and see if it can be realigned at the cat/mani whilst the system's off (again..)

cheers