It is the wires most of the time if you have a good opti or new one. I would get a set you can make up your self. with the headers.6 and 8 or the hardest around the dipstick. Accel make s some good slip on heat shelding boots just a thought.

 

Exactly what I'm using with my Duralast wires and Pacesetter headers. No problems whatsoever with burned wires.