Reply To: 1999 Mustang 3.8L V6 – Rough Idle/Power Loss

[Richard Kirshy]

Something to keep in mind..
After changing the wires and plugs.
If the issue remains you may want to check or have checked the primary circuit for coil #3.
These could be useful.
https://www.youtube.com/results?search_query=testing+primary+circuit+for+coil