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

Why did you pick this product vs others?:I bought this in March for my 2014 Ram ecodiesel. My def tank fill sensor stopped working and the dealership wanted to charge me $4k for a new tank (buying just the $5 dollar sensor isn't an option). I put this in and bought a device to delete the check engine code so the truck wouldn't go into limp mode on me. So yesterday (6-25-25) about 3 months later, the gauge just shot up off the spot it had been stuck. Apparently I was right and there was a crystalized buildup on the sensor. I would recommend anyone with the issue try this before you drop the money for a new tank 👍

My DEF level sensor was going haywire and wasn't showing the correct level in the tank. Sometimes it would say empty when it was full, or full when it was running low. I was about to make an appointment with the shop to get it fixed, when I discovered this product. After reading about DEF crystallization and residue issues, I suspected my problem might be from crystals that had formed on the level sensor in the tank. With nothing to lose, I filled the tank with DEF and overtreated with two bottles of this treatment. Despite the tank being 100% full, the gage showed the tank 3/4 full. We took an 800 mile road trip a few days later, and the issue resolved after about an hour on the road. That was 2 months ago, and the problem hasn't returned. This will now be part of my maintenance routine whenever I change my oil. Highly recommended!

Works! Got me off the side of the highway. 2019 Ram 3500 Dually. 6.7 diesel. Probably just a band aid but it worked. Along with their other diesel additive. The red bottle for diesels. The best additives I’ve ever used.

I used this in DEF tank since I had been geting P20EE codes regularly. I could see crystalization around pour tube, cap, etc. I put this in, then I got the dreaded Poor DEF Quality message and P20EE code again. Then it went away. A few miles later, back again. Then after a few days. maybe 75-80 miles, no more codes. Took a long trip of 650 miles, plus local driving, code and DEF message have never appeared again. Seems to do the trick. I also add in the Rislone maintenance DEF fluid product. Seems to all be working as intended.

Exelente producto tengo un Kenworth t680 lo uso regular y jamás e tenido problemas con el sistema de SCR mi camión tiene 739000 millas

Maybe it’s just me .. maybe my 22 Ram Cummins has a gremlin … but I tried this 3 different times and each time it caused the message to pop up on my dash display informing me that the DEF system has a problem and I needed to return to dealer for repair. The third and last time I tried it I got the same warning so I siphoned the tank dry and refilled with fresh DEF and I have not had a problem since. I’ve always thought highly of the Rislone brand but something about this stuff didn’t work for me. Maybe it’ll work for you???

This cleared all my low quality DEF alerts. I also noticed my truck is back to using the original amount of DEF as when I bought it. Definitely cleans the lines and DEF heater. Amazing product

I added a dose of this to my tank as a preventive measure to keep everything in good working order. Never had a problem with anything prior to using this stuff. The "Poor DEF quality" warning light was displayed soon after i added this to my tank. After running the truck until DEF was around 1/2 tank, I topped the tank off with DEF and the warning light went away on its own and I haven't seen it since. I never noticed any actual problems but my Duramax L5P didn't like it. It could have been the DEF that I added when I added the product--i have no way of knowing. I've always bought Peak BlueDEF and never had a problem except when i mixed it with this.