Anyone ever heard or seen exhaust plugged up or clogged passed the cats?

I'm actually experiencing that on my truck. I had a small exhaust leak in the beginning nothing that was seriously loud or bad but just a small leak i planned on fixing it soon. Well i had started having acceleration problems and this roaring noise is bout the best i could describe it. So i hollowed out the cats still didnt fix it. Then i greased my front wheel bearings because they needed it and just thought could be something stupid still not the problem. Now when i got the truck it shifted so hard in 1st 2nd and 3rd it would almost give you whiplash lol probably not that bad but damn close. So it started feeling like it was getting worse. So found someone that had a rebuilt trans to just swap it out with a new converter. I looked for one to do myself but where i live now it would be super difficult to swap a trans out. I could do it but would not be great idea i dont like putting my truck on a piece of plywood doesn't strile my fancy of things i look forward to doing. Lol but got the trans swapped and then it shifted perfect like a new truck and then that roaring noise and my poor acceleration and performance is back to ****. Well i had enough of the exhaust leak which i felt got a lot louder than it was. I got some exhaust tape to temp fix it so i can hear whats going on and it sounded amazing as soon as i pulled out on the road and gave it gas boom it blew the repair tape off. And it dawned on me the damn muffler or something is plugged or clogged i went back put my had on the pipe by the bumper and barely anything was even coming out of it.. So now im goin to get some exhaust pipes from someone. Only downside is it doesn't have the O2 sensor hole for me to put mine in. Will it cause me any problems without the o2 sensor. I don't wanna start new problems also??

On my '06 Jeep Wrangler..... the pre-cats, just off the manifold, disintegrated (due to an exhaust leak) and the pieces clogged the main cat in front of the muffler.

Apparently, an upstream exhaust leak can destroy the cats.

Potentially, your main cat (or muffler) may be clogged.

After I bought WCJr (the truck in my avatar), I discovered it had been under some water at some point. I tried to fire it up after putting an engine in it and the right side exhaust was plugged up with mud. The left side blasted mud all over the floor.

I did see a Nova blow out a pair of brand new mufflers after the shop installed them backwards.

I've had a few vehicles where either a precat or main cat disintegrated and clogged up the stuff downstream. My 94 Sierra is starting to get that way. Previous owner had a single to dual muffler and tailpipes done at the muffler shop. I can hear the main cat rattling, and the donut gaskets on the backs of the manifolds need replacing about twice a year. Gonna let it ride until either the cat pukes it's guts into the muffler (can't mistake that event) or I take it off the road to do the cab corner repair panels (bed has to come off, so it'll get box and body bushings, exhaust work, etc.).

Cat came apart on my 98z71 and clogged muffler

For the fuel Injection to work at optimal performance for power and feul economy yes u need the o2 sensors it will however run with out them

Removing the O2 sensor would ruin the performance. The computer would go into "limp mode" and run just enough to get you down the road.