I recently replaced the radiator, lower intake manifold, and changed the tranny fluid with filter and gasket. I have changed the plugs and wires in the last 50k miles. This problem was not happening before I changed the radiator (due to it busting). After I changed the radiator I decided to change the thermostat and gasket. One of the bolts was cross threaded thanks to my local shop(they recently replaced the lower intake manifold as well). I went ahead and took that job on myself this go around. I followed forums on here and chiltons in replacing it. After replacing testing it, it would stutter at around 2500k rpm. So I replaced the tranny fluid as I haven’t done that since I received the vehicle from my father in law approx 5 years. When I was done there was a small amount of white smoke from the tail pipe but it quickly subsided so I decided that fluids got into exhaust during my “maintenance”. I also noticed directly from the cat converter there was white smoke. In park or drive it stutters and shakes at 2500k rpm and up. Mostly it does not want to even get passed that rpm range I can put it in 1st or 2nd and od and drive just fine until that rpm range. I disconnected the sensor at the cat and disconnected negative battery terminal in hopes it was that. I also cleaned the maf at the air intake. Learning from other threads to no avail. Any help would be much appreciated it’s racking my brain and at this point I’m NOT quitting on it, but am unsure of the best economical point to start at. I was thinking fuel filter as it sat for many weeks before all this was performed and got started back up( which it did like a champ). I love these little vehicles. Thank you in advance.

i read on a few forums about to much fuel or other fluids getting to the cat could cause failure that coupled with the smoke I saw directly out of it I thought maybe my cat was failing. As for new fuel filter I just thought it odd for it run fine then after working on it, that the fuel filter would have failed

Update I have, replaced fuel filter and ran sea foam in tank, as of yet no luck. The stuttering are now varying in the rpm range it’s like at 1500 them it will go past it then again at 2500 and 3k. But at 3k it won’t get passed that point. I am attempting to run it low on fuel and sea foam it again to ensure bad fuel isn’t my issue