Mustangmaster

About the past 2 or 3 months I have had this skipping/missing problem with my Ford Racing Cold Air Intake and the 87 octane Brenspeed tune. If I fill up with 93 octane and run the 91 tune, it runs perfectly. The car has always run the best with the 91 tune but in the past running the 87 tune didn't miss or skip. Does anyone else have this cold air intake with Brenspeed tunes with this same problem? Is there a fix or is the fix to just run the 91 tune?

I'm wondering if some of my coil packs are not 100% because I also have Granatelli MPG coil packs and the car sputters/misses so badly with them on, the car barely runs. Now to a much lesser scale, the stock coil packs are starting to miss/skip. With the stock coil packs it's just an occasional miss. Maybe once every 5th acceleration from starting from a stop light/sign.

Nuke

As soon as you mentioned the aftermarket COPs I twitched. They tend to be prone to problems. But if you're also experiencing the issue with the OE COPs, then the first thing I'd do would be pull the plugs, followed by running a tank of SeaFoam, then go from there.