There is an engine code on the bank 2 catalytic converter in my 2007 Honda Odyssey EX-L, I paid for a diagnosis from a mechanic and they recommended replacement of the bank 2 catalytic converter. I bought this part:
The two are fairly the same. The only "real" difference I'm seeing is the location/direction of the O2 sensor bung (after cat, so on the outlet side). You could easily check this on your vehicle against the one you purchased. All-in-all, bank two is usually the rear facing bank on an engine mounted sideways. The DAVCO 18158 appears to be the rear cat. I think you're in good shape and have the correct one, but double check the position of the O2 sensor first. For your sanity's sake, according to what I'm seeing, both O2 sensors (bank 1 or bank 2) should be pointed towards the left side (from the driver's view) of the van.