Rislone 4784 DEF Crystal Clean™ Diesel DEF & SCR Emissions System Cleaner, 11.8 oz

We have a 2016 Ram 1500 Ecodiesel and prior to using this product I was eating up half a tank of DEF every month. I ran back to back bottles and started using the DEF at our local Fry’s store. The DEF consumption went down dramatically. Folks, this stuff really works. We are having to fill the DEF every two months now. Fantastic product and works extremely well.

I bought a used 2021 F250 with 75k miles. At first it was drinking DEF. I used 3/4 of a tank on a 900 mile road trip. I used this product on the first tank on my 5900 mile move to Alaska from Virginia. The first 3/4 tank of DEF, with the product in it, got me to Indianapolis, about 800 miles. The second tank I started using the Rislone DEF Treatment in every box I put in the truck, it got me to Mitchell, SD which was about 1000 miles and I used half a tank. About 1200 miles later I put 1 box of DEF in before I crossed into Canada, and stocked up on 3 boxes knowing I had about 3k more to go. Keep in mind, I'm hauling a 20ft enclosed trailer full of all my earthly possessions, and I have quite a few tools and heavy things. Something happened after that first 3k miles. I made it the next 3k miles and only used 1/2 tank. Now when I fill up it says 7500 miles to empty. I don't know if that's true, but it's been a long time since I've had to buy DEF.

Worth the try. I own a 2015 Volkswagen Golf sportwagen TDI. I would always have a check engine light with a P204F00 code for Reductant System Performance Bank 1. After taking it to the dealership and a bunch of replacement parts I still had the P204F00. At this point everything dealing with emissions was pretty much replaced. I saw this product and figured id try to clean the DEF fluid. I had about half a tank of DEF in the tank, poured half the bottle in and let it sit for 8hrs. Topped off DEF with new fluid. Took it for a hour and a half drive forcing it to regen. Got home and let it sit. Next morning the code and check engine light was gone. It’s been about 3000 miles since the cleaner was added and the codes haven’t came back. Well worth the try.

As advertised

As always, I'm skeptical when it comes to product performance—but this one? Amazing. I never owned a diesel until I bought my '21 GMC HD2500 Duramax. I love it, but man, diesel engines demand preventive maintenance. You can't wait for things to break—you’ve got to stay ahead of it with products that help reduce or even prevent issues. This particular product is excellent. Since the day I bought my truck, I’ve had nonstop problems with the DEF tank sensors sticking. Sometimes it would show full when I knew it wasn’t, and other times it claimed to be half empty right after a fresh fill-up. Totally unreliable. And what did the dealer say? “It’s inadvertent.” That word should be banned—it’s just an excuse to ignore a real problem. Let me tell you—this product works. Period. And it worked fast, too. Absolutely amazing.

Well I've never had a problem with my 2024 6.7 Cummins I put about 50k miles a year on it. And I use this about every 7k miles.

This stuff actually works. My 22 Ram had nothing but issues with the Def system, this stuff clears the codes multiple times

My 2018 gmc terrain diesel kept popping up telling me that the exhaust fluid is poor and that after 99 miles my vehicle will not go over 65mph. But every time it came up it said the same thing, it always said 99 miles. I use the premium DeF and I’m not sure how there was an issue. I purchased this product because it says it clears the fluid, also said it could take days of driving before the product fixes the issue. I’m a daily driver and spend a lot of time I town and on the freeway, I’m going on 2 weeks and still the warming comes up sporadically. It still says I’ve got 99 miles, I guess ima have to find somewhere or someone to flush the Def system, sucks cause I really hoped this DEF crystal clean additive would do as it advertises. :(