Tool Review: Rislone Cat Complete, No.4720

March 10, 2023
Reviewed by Lou Fort, Lead Technician, K.A.R.S. Inc., Huntingburg, Ind.

Q: How did the product function as far as saving you time?

A: Rislone Cat Complete is hard to classify as a “time saver,” but I suppose it could be if it works as intended.

Q: What kind of setup was involved before using the product?

A: Proper setup only involves following the directions for use, primarily by knowing how much fuel is in the tank.

Q: How easy was it to use?

A: This product is almost as easy to use as filling up the fuel tank.

Q: How was its packaging? Did it come with any accessories?

A: Rislone has covered the box with promises/claims of what the enclosed bottle of elixir can do. It has usage instructions clearly listed, and four of the main codes its intended use may solve. There’s a promise of your money back if it doesn’t work for you.

Q: What features did you like?

A: The only feature that I liked would have to be that it’s a detergent and cleaner in one.

Q: What features didn’t you like?

A: It’s not a feature, really, but I am not a big fan of elixirs such as this. However, the money-back guarantee helps. While it won’t be Rislone’s fault, I also wonder how many will follow the instructions as they are given, as it will make a big difference, I’m sure.

Q: What types of jobs/repairs did you use this product for?

A: I tested the Rislone Cat Complete on four different vehicles to best judge its effectiveness. The first one I tested was a 2004 Tacoma with over 500,00 original miles. For the past year, we have been resetting a pesky P0420 on it about once a month. My second test vehicle was a 2012 Honda Odyssey that we replaced the head gaskets on. It had a P0420 set just prior to the bad head gasket diagnosis. The third test was with a 2009 Ford Focus, this one had been extremely neglected. My last test vehicle was a 1999 Ford Taurus with just under 400,000 miles on the clock.

After a few weeks of checking up on my subjects, I can report a success rate of 50%. This is and isn’t a surprise. The Tacoma would set the P0420 prior to using this product anytime It was test-driven in check mode. After two treatments, one week apart, it did not set the P0420 when tested in the third week. The Honda has also not reported a check engine light issue since the repair. As for the neglected Focus and old Taurus, both still suffer cat codes. Given the Taurus is known to use oil and the Focus is in rough shape, I would have been surprised if it had cured these codes.

Q: Have you used other similar versions of this product?

A: Yes, I have used several professional fuel/exhaust treatments over the years, going all the way back to the MotorVac. Only two of my previously used treatments yielded better results than Rislone’s Cat Complete. Both of those products involved an extensive, time-consuming application, though. These were easily five times the expense, too.

Q: How would you rate this product overall?

A: I feel there should be more “It may” and less “it will” marketing on the package. It’s a product that may save you big money, but then again, it may not.

About the Author

Lou Fort | Lead Technician at K.A.R.S. Inc.

Lou Fort has worked in the automotive industry for 47 years and is the lead technician at K.A.R.S. Inc. in Huntingburg, Indiana. Throughout his career, he has worked for Ford, GM, and Chrysler dealerships, but the majority of his time has been spent on the independent side. Fort holds an associate's degree in applied science, along with a year spent studying mechanical engineering. 

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