I did have an intermittent miss under load on cylinders 1,2, and 5. The misfires were also present whenever I would spray the engine down to clean it and I could see it arcing all over the place, so obviously the coil pack was cracked. Which is what made me decide to replace it and hope that it was the cause of the miss under load. I did some searching around for a more reliable coil pack when I ran across the mustang coil pack swap. I also work at a Ford dealership in the US so the parts were easily accessible, so I figured why not try it. I was amazed at the difference it made. The misses we