I have a 98 civic ex 5speed it been having a problem with it bucking while driving it only does it after driving it for 3 day but when it starts the rpms will start jumping up and down then the whole car will start jumping as i speed up
i have also gotten a code once for random miss fires in each cyclinder

I just replaced
Distributor
plugs
plug wire
fuel filter
fuel pump relay
fuel pump
battery
therostat
speed sensor


I checked for vaccum leaks, timing seems to be in order, plug gaps, and spark all seem fine

i do have a cold air intake and obx muffler with hollowed out cat

 

Watching this, I have the exact issue on my 95 and asked for help last week.

 

have you checked your TPS and MAP sensors and have they ever been changed since owning the car?