Gutting firewall cat
 

I have an 03 Escape 3.0L that has clogged cats. I've replaced the one next to the muffler and have removed the front (left) cat for replacement. The firewall cat is my problem. No problems getting to it, but I see that three bolts are already broken off. If I try to remove the three that are still there, obviously they may break off, too. Can I gut or partially gut this cat and not have any issues, or is there a way to fix the issues? Or do I just simply need to bite the bullet and pull the head? Thanks!

I am assuming the cat is part of the exhaust manifold. the proper fix is to remove the manifold and broken bolts. the best way to do this is to weld a nut onto the broken stud. Anyone who drills and extracts broken studs is asking for trouble...ie wrecking the cyl head.

Yes, it is part of the manifold. I already know the proper thing to do, as stated in my original post. I was asking if I can partially or fully gut the cat and still get a decent result.

if gutting your cat means removing the substrate; yes, it will remove any exhaust restriction caused by a melted or broken cat. a p0420 will set and always be on. it will drive fine but fail any I/M testing if that is a requirement in your area.


the broken manifold bolts will cause a exhaust leak; the air that is drawn in will skew the 02 sensor creating a false lean condition, the pcm will enrichen the fuel mixture...running rich kills cats...clogs egr passages.


if you have vvt, you better not leave any crushed substrate dust in the cat or it can get sucked back into the engine and score cylinder walls.