Donnie the CCX uses a slip fit as you've seen on your car. Make a (sharpie) line where the headers go into the sidepipes. The sidepipes are really easy to remove, two tabs on the slip joint and a rear hanger. If you take your headers off and try them one at a time in the sidepipes you will quickly see first off if they aren't going in far enough from your line and also if any have loosened at the joint. A good exhaust shop can expand them to get a good fit as suggested. If they aren't going on far enough I make tabs for the exhaust to replace the original style. You can give them a little snug up as needed to keep that joint tight. I use a 1/4-28 grade 8 screw through them with a mechanical locking nut.