2004 Quest broken bolts in RS exhaust manifold

[schuylkill]

So I'm working on replacing catalytic converters and flex pipe and it's a rusty mess. On the firewall side cat I snapped off one and probably two of the bolts that come up from underneath into the mounting flange for the cat on the manifold. Looks like once the cat is out there is room to get to them, I'll know more on that later, but looking for suggestions on the best easy out to use in this situation. The Erwin set I have has worked for me but I've never tried it on large size bolts like these. The small square flats on these tools don't give a good setup for getting on a wrench to get good grip and force. Suggestions?

[VStar650CL]

You can use a 12-point socket or flatwrench on a square-ended easy out, or they do sell 8-point sockets for use with carriage bolts.

[schuylkill]

I gave up on drilling that bolt. I have a small beefy clamp that I'm going to use in its place. I'm exhausted. I did find that the LS cat apparently suffered extreme heat at some point, the honeycomb is cracked and the surface depressed in a small area. I have everything off, need to get some new hardware to replace the badly rusted nuts and bolts on the flanges on the flex pipe. Would it be wise to replace the bolts that mount the cats? Studs and nuts came with the cats but no bolts. Rain tomorrow so I get a break. I have to work out in the stone driveway, no garage. Hopefully this fixes my CELs as mentioned in another post.

[VStar650CL]

I did find that the LS cat apparently suffered extreme heat at some point, the honeycomb is cracked and the surface depressed in a small area.

You're lucky you caught it, then. The next step after superficial melting is either total blockage or disintegration, and the latter means cat inhalation and bye-bye engine.

With cats I don't recommend replacing anything you don't need to if it looks rusty enough to break. You've already experienced the reason why.