Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 16oz (120007)

This WORKS! Car ran sooo good after! I used this product during a fill-up and it was simple to add no mess and no fuss. After a tank or two, I noticed smoother idling and emissions seemed cleaner. Cleanliness: Helped clear some buildup and soot over a few uses with speed. Leakage: No leaks during application pours cleanly. Durability: N/A (single-use additive) but bottle held up well. Product quality: Feels like a solid formula nothing spilled or stained. Longevity: Results seem to last a couple of tanks after use.

I used this on a Porsche Boxster with 55,000 miles. Got a “check engine” light, and the code was for the catalytic converter. Figured I had nothing to lose. Followed the directions to add to 1/4 tank of fuel, and the the code did not clear. Figured I would try another bottle. The code then cleared in about 10 miles. This was all over 1000 miles ago, the check engine light has come back on and there are no pending codes. I am sure this stuff won’t fix every catalytic unit. In Given the cost of a new catalytic unit, this is a bet worth taking.

Can’t give 5 stars because it didn’t help me at all. That being said not saying it doesn’t work, it just means my converter might need to be changed

If you are facing a failed emissions test, don't give up on your catalytic converter until you try this. I recently failed my state inspection due to high NOx levels—my readings were hitting 700 PPM, which is well over the limit. After some digging, I realized my downstream O2 sensor was dirty and essentially unresponsive. How I Used It: I followed the "1/4 tank rule" for maximum concentration: Waited until my gas tank was at exactly 1/4 full. Poured the entire bottle of Cataclean in. Immediately hit the highway for a long-distance drive. Drove it hard until the gas light came on before refilling with fresh fuel. The Proof (OBD-II Data): I monitored the entire process using my BlueDriver Bluetooth OBD-II scanner. It was incredible to actually see the live data change. Over the course of that highway drive, the downstream O2 sensor readings began to stabilize and "wake up." The graph went from a flat, sluggish line to responsive, healthy signals. The Results: I went back for a re-test and passed with flying colors. My NOx dropped from that failing 700 PPM down to an average of 75 PPM. Final Verdict: This product isn't "magic in a bottle" for a physically broken or melted catalytic converter—if it’s dead, it’s dead. However, if your fuel and exhaust systems are just carbon-fouled or your sensors are too dirty to read correctly, this stuff is a lifesaver. It saved me from a $1,000+ repair bill. Highly recommended!

This is my story. My Honda Odyssey EX-L 2005 (85K miles, first owner, bought new, all regular maintenance) all of sudden had a CEL light on 11/22/2016. It threw a code of P0420 pointing at catalyst system efficiency below threshold (bank 1). Based on my research, there are too many things that can cause this code. However, if it comes to the catalytic convertor or oxygen sensor replacement, the expense could be too high. So, I decided to take care of it myself before I go to Honda dealer or other mechanics. I first changed the engine oil at Walmart, just regular Quake 5w20 oil. Besides, I asked the technician at Walmart to add a bottle of Lucas (heavy duty Oil stabilizer, white bottle) as well because the engine seems to burn a bit oil over time. I also filled the gas tank up (regular 87 gas) and added a bottle of Heet (red bottle, Heet Fuel Line Antifreeze, Water Remover and Fuel Injector Cleaner) into the gas tank to remove water and hopefully to clean the fuel injector. Then I cleared the code myself and started driving the vehicle locally. After driving about 135 miles, the engine light was on again and had the same single P0420 code. At the time, the Cataclean I ordered from Amazon arrived so I want to give it a shot. At this weekend (12/03/2016), I already drove the car for about 190 miles since I filled the gas full. I poured the whole Cataclean into the gas tank, which had a bit less than a quarter tank of gas. Then I drove on to highway. As some reviewers suggested, when there were no cars close to me, I stepped on the gas pedal hard (almost 'floored' it) to get RPM to 5K. When the RPM reached 5k, the speed of the car was about 85 miles on highway and then RPM immediately fell back below 4k and 3k itself. I released the gas pedal to slower the car. (If you do that as well, do be careful. Nobody wants to get a speed ticket on high way, right?). I did the same cycle for about 5 times on highway: slowing down to about 60 miles/hr -- flooring gas pedal to reach 5k RPM (speed over 80 mile/hr) -- releasing gas pedal to let the car slow down. After driving about 30 miles, I stopped in front of a mall to shop a while. About 15 minutes later I came back to the car and started it. You know what, the engine light was off, on its own! I drove another 40 plus miles after that and stopped at a gas station to add some fuel. I just added 6 gallons of regular 87 gas. As I do not plan to add premium gas in the future, I did not want to do it now as some reviewers suggested. With 6 gallons of fuel, I drove more than 120 miles before I filled the gas tank again. That 6 gallons of gas gave me about 21-22 miles/gallon gas mileage, which was about right for Honda Odyssey. The engine light is still off (after driving 170 miles). I felt the car was getting more power after adding the cataclean. The acceleration was smooth and more powerful. I did not observe any black smoke (or any kind of smoke) from the tailpipe when I floored the gas pedal. The car did not have any driving issue or noise or anything. I did not expect it worked so well when I did not see any smoke or anything coming out of the tailpipe. But obviously it helped clean the catalytic convertors or oxygen sensors or whatever that threw the P0420 code. I am not sure how long the code will be off and I will post a follow-up comment in the future. Again, the car has been maintained regularly for oil change, transmission flush, and I added sea foam to gas, oil gasket, and even brake air intake lines once every other year. However, the car was driven mostly local in the past 4-5 years. I can tell you, its RPM never reached 5K in the past 5 years. What causes the P0420 code? I do not know. But obviously the Cataclean did help at this time. Spending $16-20 on the Cataclean before you touch the expensive oxygen sensors or catalytic convertors could be a good investment. I plan to buy another bottle in case the code comes back again. Good luck to you DIY maintenance.

I'll try to make this brief. I used Cataclean once about a year ago on recommendation from a mechanic and various online sources as a stop-gap measure to keep the engine light off for enough miles to pass inspection with a P420 catalytic converter code. This also required turning off the light with an OBD scanner first, adding the Cataclean, then driving over 100 miles and resetting the I/Ms. It was successful, but I can't say if the product helped keep the CEL off or if it just happened to work out. After inspection, the CEL returned at 280 miles, which it always will, this is not a permanent fix, please understand that. Now comes the very, very bad part. This year, each time I turned off the CEL to see how long it would remain off before inspection, it came back on well before 50 miles. So I know my catalytic converter is getting worse, no way to make it one more year, it would have to be replaced. But I thought I'll give Cataclean one more try and maybe it will help keep the CEL off a bit longer before I commit to $2,000+. Cleared the code last night. Added the Cataclean, precisely as directed, 1/4 tank, etc. Started driving. Within ONE mile, massive misfires, chugging, struggling, no pickup, CEL FLASHING. I had entered a highway on ramp when it hit, managed to get up to speed at least, then exited immediately. Vehicle shaking and sputtering at stops, I put it into neutral and gave it some gas so it wouldn't stall. Drove to the nearest gas station and filled the tank to at least dilute this garbage, the best option at the time. I ran my OBD scan at the gas station, P0300 random misfires code, all cylinders reporting misfires. Cleared the code so I could see how fast it would return. I drove only around my neighborhood so I wouldn't be far from home if catastrophe struck. The CEL of course came on again in a few miles but the jerking, stuttering, shaking and struggling were greatly diminished now because I diluted the additive with premium. The problem remains, however. When the CEL came on again, at the very least it was steady and not flashing, certainly because of my quick thinking to dilute it. Now I'm in the unenviable position of HOPING it's JUST the catalytic converter that got badly clogged from the release of filth or whatever the product released into the system in the single mile I drove it after adding it to the tank. Did the research online. It could be a lot of system components affected in addition to the already weak cat. Look it up yourselves, PLEASE! This can foul your spark plugs, fuel injectors, O2 sensors. It can severely damage your cat when you have misfires, causing it to overheat and break apart. There are tons of articles about all the possible side effects of using this. I never came across them when I researched it the first time because I didn't specifically search for these side effects. All I saw were opinions that maybe it will work out, maybe it won't, but that it was safe. THIS IS NOT A SAFE PRODUCT! Look, maybe it's OK for some people - it doesn't work at all for others. A very mildly dirty cat might be cleaned enough to get through an inspection and turn off the CEL for a while longer than normal but - wow. Did I ever make a huge error using this again. Yes, nothing happened the first time I tried it. You might get lucky. You also might release so much gunk into your engine and exhaust that you destroy your vehicle to the tune of THOUSANDS. Do the research. Be smart. I poured this junk into my tank without a care in the world, thinking it would either help keep the CEL off or not and that would be it, never suspecting massive misfires and a flashing CEL. It's a holiday weekend now and I can't get to a garage until Monday. I will update this review when I learn the extent of the damage and I'm hoping it's only 2K for cat replacement. Imagine that. Think long and hard about trying this. I hope I can save some of you from the scary situation of being on the highway and misfiring and struggling to get up to cruising speed and a nerve-wracking drive back home or having to call for a tow. Consider this a public service. Get online, find out everything about this and other additives before using them!

This stuff works pretty well. I had catalytic converter codes on both banks of my 2009 GMC Acadia. It actually cleared one of them.

Worked for me, 2013 Niss Altima CODE P0420 Erased. (02 Sensor or Catalytic converter clogged) Pass inspection with no issue. Highly recommend it, follow simple instructions.