I hope this isn’t a sacrilege since I’m new here but I would encourage anyone who has a diesel GC or Liberty and curious about CB Engineering to read through the various threads on the CRD on JeepForum. Not to drive any traffic away from this site but there’s a wealth of info about all the same questions asked here: trouble codes, DPF, ERG, turbo actuator, swirl motor, etc, etc.
Pay particular attention to postings by “tnadanzig” as that is the same person who owns CB Engineering and developed the products offered there. The threads I referred to document the development of some of these products in considerable detail - certainly waaay more than shown on the website - backed with lots of photos of the part development.
Definitely worth some time to check out if you want to understand your rig’s engine.
I have the proflow on mine with 15000 miles and no issues. The Clamps are extremely solid and It wasn't hard to install. You do have to trim about 6" of pipe to get them to fit but that's pretty easy. So far I love them and the sound!!