P0305 misfire

Guess what folks, my car is once AGAIN misfiring, here is my original thread

http://www.2carpros.com/questions/chrysler-sebring-2004-chrysler-sebring-p0301-code

Now everyone kept telling me to change my engine, I did!, and here we are again with the misfire. This time its in cylindar 5 and 3 (P0305, P0303) and it throws the generic code P0300. Anyone have any idea's since it now has a new engine? And its not any of the basic stuff, like changing the spark plugs, oil, coil pak etc... I have tried ALL that in the past. It seems like the only thing left is the computer itsself, because once AGAIN there are NO signs there is anything wrong with the car, no stumbling, no hesitation, nothing just the pretty little light saying there's a misfire!