I have a '08 2.7L charger. For the past year so my cylinder no. 1 has been misfiring. I've had a tuneup, changed all the ignition coils( no.1 more than once), spark plugs, etc. It will temporarily fix the problem and it will run smoothly, then the check engine light comes back on and it begins to misfire and run roughly. I have even taken the step to change the O2 sensor on that side, and the check engine light can back on within a few hours. Sometimes it goes off by itself for a few weeks and runs good then sometimes it says on for weeks. It has always been driveable but I'm trying to get to the source of the problem. Any ideas or suggestions?