Snibble, what are you attemting to do? Replace the catalytic converterand/or muffler?

I use the thin wafer wheels approx. 1" in diameter to cut metal pipe. It's important to have access around the entire pipe though so that you can keep the cutting wheel straight in the slot. Otherwise the thin wheel will break off as they can't tolerate any twisting or lateral loading. Be sure to wear safety glasses.

I suspect that your inability to get this particular clamp apart prevents it, but it would probably be easier to drop the entire exhaust system and work on it out from under the car.

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Fred Hoelzle