How often is it becoming 100%? I've heard/seen of bad DPF when it just wears out and has to be replaced. I'm assuming you do get some highway time often to help keep it clean?
Welcome! For suspension parts, you get what you pay for a lot of times. Usually Rough Country is cheaper, and here is someone that used one: https://www.ecodieselram.com/forum/threads/rough-country-4-inch-lift.2677/
But, hopefully more members can chime in and help you out.
Sticker on the ECM maybe? Otherwise not without some expensive equipment to pull the tune and see what's there... even then you'd need the skill/experience to know what you're looking for.