bogging down while accelerating

I've got a 94 dodge ram 2500. My cat. converter recently became plugged up and my truck began to bog down severely anytime I applied a little more than light pressure. I busted out the guts of the cat. hoping that a chunk of honeycomb was preventing full exhaust release. This did not fix the problem. If I apply a little more than light pressure to the gas pedal the truck completely bogs down and almost begins to buck until I let go of the gas. There is no backfiring. A month ago I took it to the dealer to have a check eng. light diagnosed and they told me my egr valve was the source of the CEL. But at that time the truck ran fine. When I cleaned out my cat I noticed that the O2 sensor had what looked like a dent in one side of it. I could have possibly damaged it while I was busting up the cats guts. Would a damaged O2 sensor cause this severe of a bogging down problem? I can't even get the truck up to 2500 rpms.