I'm doing some bathroom plumbing work and saw this under the sink. The sink and the shower drains both have PVC going straight to this thing, which is then attached to the toilet and main sewage waste pipe. So these 2 drains don't have their own p-traps. I'm planning on separating them out.
I'm guessing it's an old version of a p-trap, but is it anything additionally special? Looks more intense than just a trap. Any caution against cutting the metal and connecting PVC to it?