You can find cleaning kits that hook to an air compressor as well as the dpf cleaning solutions on Amazon and other stores. They are great to run through it at least once year. But if it's super clogged up use a bug sprayer and vinegar, hit the front opening as well as all the sensor holes really good, let it sit for about 5 min then use a garden hose with a narrow sprayer or a power washer if you have one. It's going to make a heck of a mess and kick out a ton of garbage. Tilt it straight up to drain the water the best you can. Then slap it back on the truck, put it in 1st and drive with high rps, you'll know when its good to go because your engine will roar back to life and you'll see a massive plume of smoke blow out the exhaust. You might have to buy an obd plug in for your trucks computer (i used a Bluetooth one i bought for like $30) and hit clear codes when it goes into limp mode to bypass the safety so you can achieve high rpms to blow out the clog AFTER CLEANING. It's alot of work, if you need more help let me know and I'll try and help. Good luck, hope this helps

How did you clean it? What did you use to clean it?