I just replaced the drivers side coil pack on my 99 4.6L. Had a code 304 misfire on #4. After replacement engine seemed to run fine on test drive. I removed the neg battery terminal for about 15 minutes to reset code. Truck started but ran extremely rough so I shut it off. On restart it ran okay for about 30 seconds then died. It will not restart. Checked all fuses and relays. Any ideas?

 

Quick switch you old coil back on .... what does it do then?

 

You need to start all over again.
First, did you put the plug wires on the way they came off the old coil?
Cylinder 4 is the rear most on the passenger side.
No need for 15 min to reboot the computer. 1 min will do it.
Until you have something to go on it's just guessing.
Is there anything else you did?
Good luck.