​several months ago my 97 grand cherokee 4.0 started bucking between 50- 65mph. It's gotten worse over time. I replace the output speed sensor and the TPS and the bucking symptoms went away for a day and then slowly started returning. Yesterday my check engine light came on and I have random misfires in cylinders 4 and 5.

About a month before the bucking started i got a check engine code saying the catalytic converter was bad but the light went away and I forgot about it.

Could i possibly actually have a bad cat that is causing bucking and throwing my misfire codes?

My cam sensor and crank sensor don't really have more than 20k miles on them. Any opinions would be awesome, thanks!