2004 Outlander catalytic converter: help
 

I purchased an 04 Outlander whose exhaust system is patched together with JB Weld. I'm using EBay to find inexpensive replacement parts. I found a good front pipe, but don't know which catalytic converter to purchase. The ones on EBay that look like what is on my vehicle are labeled "Rear", as if there is more than one. But my vehicle only has one. Can I use it? Should my vehicle have more than one?

None of the cheap universal converters have an O2 socket, but the "Rear" converters do. My current converter has an O2 sensor on it.

Any advice is appreciated.