what causes my 5.9l magnum to spit and sputter after warming up i have replaced the plenum gasket, plugs, wires, all sensors, distributor cap, rotor, pickup coil and still no idea its ok as long as my foots in the gas but it bogs down and feels like its lost its power considerably

 

Remove the upstream (closest to engine) O2 Sensor and see if it runs better. If so, its time to replace the catalytic converter.

 

can i just bypass the converter if so what do i do about the o2 sensors

 

If the cat is clogged up, replace it. Or, empty it out.