1st Gen - 5vz-fe - Running very rich

Hey y'all, I've been scouring through threads trying to find answers but couldn't quite find any, so I figured I'd just go ahead and make my first post.
I recently made the wise decision of buying my first Tacoma in a 2001 Prerunner 5VZ. (4wd guys don't come after me, the most I'm taking it on are gravel roads to get to fishing spots. For now.)

The problem at hand is that it's running very rich (the smell from the exhaust is incredibly strong) and occasional bogging when I go to step on the throttle. The previous owner had a little too much fun with a welding torch and soldering iron and cut the catalytic converter out, straight piped it, and rigged the O2 sensors in a way where "it wouldn't trip a check engine light". I'm about 99% certain this is what is causing my running rich issues and bogging under acceleration.

My issue is that I'm unsure what pieces I will need to bring this exhaust back to fully functioning. The Haynes manual just shows diagrams for a "2wd" system with only one catalytic converter and a "4wd" system with 2 catalytic converters. I'm not sure, with it being a Prerunner Xtracab with a 6' bed, which I will need.

Also, any suggestions on other pieces that may be causing this issue or quick fixes that may help lean out the system while I'm waiting on parts to come in would be greatly appreciated. I've cleaned the MAF, replaced the spark plugs, and am about to replace the TPS this weekend. I've read some posts about the coolant temp sensor or ICV potentially causing fuel mixture issues, but I figured that the most glaring issue in the redneck engineering was probably the cause.