2000 Ford Ranger Exhaust sound sluggish power and shaking.

1. Make and Model of your car
2000 Ford Ranger
3.0 v6 4x4
2. Current odometer reading (approx)
113,000
3. Stick Shift or Automatic Transmission
5 speed
4. Strange sounds or smells (if any)
I have no muffler on my truck so it is straight piped and the other day it sounded worse than usual like there is something in the way of the exhaust coming out and at the same time it shakes in all gears when I push down the gas pedal.
5. Fluid leaks (if any)
no fluid leaks that I can see
6. Past repair history (if applicable)
Just replaced plugs and wires and oil change about 2 months ago.

What my question is, is that the other day while driving my truck at the same time started to shake and a weird sound coming out of the exhaust. I have cut the entire exhaust system off behind the 2nd catalytic converter so all I have is manifolds back to 2 cats. When I start it up the sound of the exhaust is different then before like something is on there clogging it up and in every gear the truck shakes. I have heard from a few people that it might be a clogged catalytic converter. If you could please let me know what this could be.