O.k. as of this morning, it feels as if the car has a rougher idle than it has been.
also I changed the plug wires, and it was no help.

I have pulled 4 out of 6 plugs and they all look like they are almost new, I even pulled the hardest one to get to, just in case someone didn't change it when they changed the others.

Plugs are Autolite 606

How is your coolant and oil level?

Without an idea when they were changed it is hard to tell how worn out they are.

I know opinions vary, and I stay away from Autolite. I've had many cases of [replace Autolite with factory plugs] to fix issues. Including a friend'* `98 LeSabre with new Autolites and a rough idle.

There are many different kinds of Autolite 606 out there, ranging from get-it-out-the-door quality to double platinum. Your picture of the spark plug from earlier is out of focus where the electrode and ground are, so I can't tell how worn out it is. Based on this, I can't tell what caliber of 606 you have nor can I estimate how worn out it is.

ACDelco 41101 Iridium is factory stock for your car, and it'* what I run in my 3800 with no issues.