DIAGNOIS ON 2004 NISSAN SENTRA/1.8 ENG NUMBER 2 MISFIRE. PARTS CHANGED EGNITION COIL AND SPARK PLUG. LIGHT CAME BACK ON. DIAGNOIS MISFIRE NUMBER 2. WHAT COULD BE CAUSING THE SAME LIGHT AND CODE TO COME ON AFTER PARTS WERE CHANGED?
Could be low compression in that cylinder or a dirty/defective injector.
If you have a high tech state of the art “mechanics stethoscope” (also known as a short length of garden hose)take a listen. is it clicking?
Or a noid light is cheap at a parts store.
Did you also change the spark plug wire(s) - or at least test them?
did you erase the code from the obdii scanner first?