Chrysler Repair: misfire #1, crank shaft, shaft position

Question
Chrysler 2006 town/country. had misfired in #1 & 4 cylinder. replaced plug on 1 & 4, still misfire, replaced wires on 1 & 4, still misfire, charged all plugs and wire, misfire on #1 and failed o2. replaced coil pack and downstream O2 senor. still back firing. What else to do. I also reset the computer by removing the battery post. What to do???

Answer
Hi Ron,
I assume you have been following the fault codes to see what remains. Maybe a compression test on cylinder #1 would be the next step. Or if both 1 and 4 are still the problem, it might be the cam or crank shaft position sensors are giving a flaky pulse on those two that leads to an issue with the injector pulsation, or the #1 injector may be leaking and that is then causing the backfire.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by Kevin.