[mark houghton]

I have one stashed away, without the fittings. Its the poor man's way of deleting the cat for less exhaust restriction, something people do where you want the benefits but have to return to stock to pass emissions testing. It came with my first 930 and was quickly shelved as I installed an after market muffler (no testing required here).
As for running without the O2 sensor, I always just unplug mine and tune the idle mixture without the Lambda system...in other words, in open loop. I don't like the Lambda forcing a lean mixture just to keep the cat nice and hot.