Re: 04 Mercury Monterey Multiple Misfire
I had the same issue with my 2006 Freestar 3.9L
It was a bad coil pack. I had multiple cylinder misfire codes as well. I thought the engine was toast. Went and got a new coil pack and an hour later poof it ran like new. Good luck, hope this helps. By the way mine was not cracked at all, just worn out.