The Nissan Path

2006 PF LE - I've been having problems with engine misfiring (first Cylinder 4, them Cylinder 3, last Cylinder 1) in each instance I replaced the Coil pack and the trouble went away. A couple of weeks ago I've got the misfiring on cylinder 1 again, so I replaced ALL the coil packs (new ones, aftermarket) . And it ran like never before, very smooth, you couldn't even feel the engine running. Last week the darn cylinder 1 started misfiring again but, this time I notice that it only does it when the engine is warm (about 10 to 15 minutes after starting). When is cool it runs like a charm, not so much after it warms up. I believe it is not a coil pack problem because when I had problems with the coils pack it always ran rough (hot or cold). I am getting ready to replace ALL fuel injectors to see if that is the problem (anyways, it's got almost 200K miles so it would not hurt). Any suggestions out there? I appreciate your assistance. Thanks!

What spark plugs are you running?

Did you inspect the bottom part of all the coils? (long piece) where they replace also? they tend to crack when not removed carefully or deteriorate over time, also check the rubber pieces that attach. A hair line crack is all that is needed for the spark to jump to ground and misfire. Avoid driving with misfires or you will damage the cats and will be an expensive fix