Ok so I gotta replace them.. no big deal they have lasted 122k. Question is should I do the plugs as well. I replaced the plugs and wired 2 years ago. *mm Magnacore and Bosch. Now seeing as I have been having Missfires on cylinder #3,#5,and #7 does it make sense to replace plugs as well.. thanks for the input.

 

yes on the plugs. Watch wires in total darkness for any arcing...

 

Will look like a laser light show if you have a wire problem.