THERE IS A DEAD MISS UNDER LOAD, PLUGS COIL AND WIRES OK WOUD CAT CAUSE THIS on 2004 Ford Ranger

AFTER SHIFTS TO OD, THEN PRESS ACCELERATOR, HARD MISS

2 answers
Ignition fire breakdown! Scope and/or scan will find it!! Can't assume any part is "ok"..! It's not the cat conv,..
Usually a plug wire issue; Do a resistance test on your ok wires to make sure they are good.