1998 Trooper Catalytic Converter Confusion

I'm kind of confused about the location of the catalytic converter(s) on my '98 Trooper. I see people saying that there are two converters--one on either side after the exhaust manifold and before the "Y"--however when I look under my Trooper I don't see anything resembling a catalytic converter before the "Y", and instead have what sure looks a catalytic converter immediately after the "Y". Is there some kind of tiny catalytic converter that fits inside the exhaust pipe without making it any bigger? Also, I do see four O2 sensors, with one on each side after the manifolds then two after the "Y", with one before and one after the (assumed) catalytic converter.

Mine essentially looks like the following diagram (taken from isuzupartscenter.com)



What has me really confused is their diagrams also show an image that looks more like what I have seen described with two catalytic converters before the "Y", pictured below



I'll try to get underneath mine today to take a couple pictures to clarify what I'm seeing. Thanks in advance for any help in figuring this out!