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🚛 Keep your diesel running clean, lean, and mean with Rislone DEF Crystal Clean!
Rislone 4784 DEF Crystal Clean is a specialized emissions system cleaner formulated to dissolve harmful crystallization deposits in diesel SCR systems. Safe for use with all DEF fluids and emissions components like DOC, DPF, and SCR devices, it restores engine efficiency and reduces DEF consumption. Regular use every 5,000 miles prevents buildup, protects your vehicle’s warranty, and keeps your diesel truck or SUV running at peak performance.




| ASIN | B0CRSY78LR |
| Best Sellers Rank | #4,196 in Automotive ( See Top 100 in Automotive ) #18 in Fuel System Cleaners |
| Brand | Rislone |
| Brand Name | Rislone |
| Contains Liquid Contents? | Yes |
| Customer Reviews | 4.5 out of 5 stars 521 Reviews |
| Included Components | (1) DEF and SCR Treatment |
| Item Form | Liquid |
| Item Type Name | Diesel DEF & SCR Emissions System Cleaner |
| Item Volume | 11.8 Fluid Ounces |
| Manufacturer | Bar's Products |
| Material Feature | Scented |
| Material Features | Scented |
| Model Number | 4784 |
| Number of Items | 1 |
| Part Number | 4784 |
| Scent | Unique |
| Size | 1 Fl Oz (Pack of 1) |
| Special Features | Automotive |
| Specific Uses For Product | Automotive DEF additive |
| Surface Recommendation | Automotive |
| UPC | 078615047840 |
| Unit Count | 1.0 Fluid Ounces |
| Warranty Description | Please see manufacturer |
T**Y
2016 Ram 1500 Ecodiesel DEF Consumption
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.
M**D
This product works!
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.
S**Y
Preventative maintenance
Decided to use this in my DEF system every time I change the oil (5-7k miles) after needing to replace the DEF tank system at 75k miles. I don’t know if the product works, as this is my first time, but if $20 every 5-7k miles saves me a $1500 bill every 75k miles then it’s worth it.
H**T
Worth the try for the price
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.
T**Y
Buy 2... yur gonna need it
As described and fast shipping
A**R
It works excellent.
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.
B**N
I have never had a problem
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.
B**L
DEF Cleaner
Seems to work
Trustpilot
5 days ago
1 week ago