4720 Cat Complete Fuel, Exhaust, Emissions System Cleaner, 1-Pack

This product is great. I have bought it twice and it makes my suv drive like new. First time had engine light on but after using about 2-3 days light went off. I've told my children and they purchased it as well.

Not much else to say, there. I followed the directions to the letter (driving more highway AND city than what's instructed) and P0420 remains on the OBD.I've been told now by two very experienced mechanics that these products rarely work - after now trying both Cataclean and this one, I now understand why they say this.EDIT EDIT EDIT!!!Just changed to 5-star because, although it took driving the car beyond what the instructions say, it has worked perfectly. P0420 is now gone, vehicle passed state inspection "with flying colors" and registration is complete.Key take-away: Give this more time to work if it doesn't do the job right away. I did nothing different - same gas as always (I fill up with Chevron or Texaco almost every time as they include Techron in their gas and my former racecar driver brother-in-law says that's the best). I do also add a bottle of Techron on occasion to give an extra "boost" to the cleaning power.

It did turn off my check engine light for my catalytic converter until my next fill up. Didn't work again.

I gave this 5 stars because while it did not "fix" my P0420 code, it made a visible difference in the contamination on my catylitic converter. The cause was contaminated 02 sensors from having to weld a cracked exhaust manifold. Removing welding flux is not the same as carbon buildup.That disclaimer aside, I did notice a VISIBLE difference in the contamination level of the 02 sensor & catalyst inside the converter. Mine had "normal" levels of contamination, but it still did a good job of cleaning things. It's worth a try, although there may be other causes of the trouble codes.

Snake oil doesn't do anything. Used it as directed and the catalytic codes came back as soon as th cycle clears. Waste of money dont buy it to clean converters

I left it 5 stars because the product fulfills what it promises excellent choice I followed the instructions as it is and it worked for me it completely erased the engine light by recommended catalyst

Used it per directions. Light went off for a tank or 2 and then came back on. Easier to pour in the tank than to try and replace cats. It may work in some situations but in mine it was short lived.

Rarely leave reviews but this stuff worked for me! Vehicle renewal coming up and CEL had kicked on, it's been weird kicking on and off for a bit but always reading the same code and having no changes in performance/mileage but this time it had been on for a bit. Was getting worried with the renewal coming up so soon and tried this on a hail mary and it worked. I have a small tank (9.2 gal) so I'm wondering if the higher concentration helped in my case.I followed the directions to a T, added stuff to a half tank, did some good speed highway driving and then some in city start/stop for the 20-30 miles they recommend. I felt like going 30 is better because the concentration of cleaner/gas is higher at this stage so you're using that treated fuel. Then I filled the tank and drove roughly 30 more miles of mixed driving, got home light still on. Later went to grab some takeout, started car and light turned off! I turned car off, took wifes car to get the food and first thing this morning drove to the inspection place and passedI'd say follow the directions to a T but also lean towards whatever leaves a higher concentration of the cleaner. I also used Premium the entire time for everything. I had even filled a tank of premium before all this hoping it might clear. The car also seems to be running a little more quiet and smooth right now

I said I would write a follow up. Put in around Christmas see review. Have now put about three tanks of gas through pickup truck. No codes have come up since. So would say it well worth buying. I had all sorts sorts of codes showing up turning on eng light had to clear every 1/2 tank.

送ってきた商品が2020年製廃棄処分品完全にだまされた箱は日焼け潰れあり最悪だ金返せ

Best !! Engine light is gone now. It’s a been a week and I am not seeing the Engine light anymore 😊

Does not work for me, and no guarantee as the described

I had an engine light come on in my 3010 Honda Accord. OBD2 scanner said it was a catalytic converter issue. I put this into my gas tank when it was about half full. After a few days of driving, it fixed it and the light is off. I've done this once a year for 2 years and it keeps working. Love it as a cheap way to prolong the life of your old car!