misfire #4 cylinder, 2000 DTS

Hello,
 
I've tried doing a search and don't seem to come up with answers I need, if the answers are already here, please point me in the right direction.  2000 4.6 DTS.
 
Showing cylinder 4 misfiring, have replaced the spark plugs and didn't improve the situation.  Can't find reference for cylinder numbers, is #4 on the radiator side, or firewall side of engine?  Can the coil pack gizmo that attaches with 8 bolts each side, be tested at a dealer?  Trying to find how to eliminate possibilities.  Noticed some moisture on one side, on the 4 spark plug boots.  Coil pack gizmo seems sealed, is there some way to try to dry it, or is it a matter of either it works or doesn't.
 
Thank you for your help,
Farmer Steve in South Dakota

My uncle is a mechanic, he told me you can take a spray bottle with the mist spray which is very fine, and spray the wires to the plugs, if they are working right they'll spark. This way you don't need a multimeter to test them. If it's not in the plugs, then it might just be in the wireset or even more likely the coil. 

SUCCESS!!!!!!!!!  Problem solved.  Ended up being a bad coil pack unit.  Problem would have been solved sooner if I were a little bit quicker on the uptake!!!  Process slowed down by my slow thought process.  I had seen in other posts about switching the coil packs to try to prove out where the problem was, but I would look at a coil pack and wonder, how the heck do you move them around, looks to me like they are all permanently in place.  Well, dufus, people were talking about switching the complete front coil pack unit with the complete rear coil pack unit.  When that finally sunk in, I made the switch, and the misfire followed the bad coil pack unit.  Got the replacement part at the Caddy dealership, and amazingly, parts man gave me about a $50 discount on the $360 part.  Put it in, and the old girl runs as smooth as can be.  Little code reader I have sure is handy for avoiding mechanic fees.

let me know if the problem comes back. I have the same problem except on cylinder 5 and changing the plugs and the coil worked for about a week, but came back on the same cylinder. Im at a loss.

Still working good.  Now I''m needing to replace window regulators.  Wish I knew enough about fixing engine problems to give you advice, but I just was fortunate my fix took.  Good luck.