Cataclean Fuel & Exhaust System Cleaner for Gasoline Engines, 16 oz

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.

Purchased this product to help clean out the exhaust system in my car and to try to clear a check engine code. I put it in today and drove it almost 50 miles. The car runs smoother and the check engine light went out. This stuff works. I am very pleased and impressed!

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

This product worked very well for me. I followed the instructions carefully, and it helped clear the code as expected. It was easy to use and saved me time. I’m very satisfied with the result and would recommend it to others who need a fuel and exhaust system cleaner.

I recently utilized the Cataclean Fuel & Exhaust System Cleaner, and it has demonstrated exceptional efficacy in addressing several automotive maintenance concerns. This 16-ounce liquid formulation, produced by Mr. Gasket Co., is designed to reduce carbon accumulation in critical components such as catalytic converters, oxygen sensors, fuel injectors, and cylinder heads. Following a single application, I observed a noticeable improvement in engine drivability, including smoother idling, reduced hesitation, and enhanced fuel efficiency, which aligns with the product's claims of potential hydrocarbon emission reductions by up to 50 percent. The product's compatibility with gasoline, diesel, hybrid, and flex-fuel vehicles, without altering fuel composition, ensures broad applicability across various engine types. Its patented, EPA-approved composition is non-toxic and unscented, facilitating straightforward usage—simply pour into the fuel tank every three months for optimal results. Notably, it assisted in clearing a persistent check engine light and supported successful emissions testing, thereby extending the operational lifespan of exhaust system elements like DPF filters. In terms of construction, the durable COEX-HDPE bottle with a long-nose design accommodates capless gas tanks efficiently, enhancing user convenience. Overall, this cleaner represents a reliable, cost-effective investment for maintaining vehicle performance and regulatory compliance. I recommend it to automotive professionals and enthusiasts seeking a proven method to restore and preserve engine integrity.

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!

Useful for newer catalytic devices but will not get a old/crack or broken unit to work.

It works very well

Vi buenas reseñas en internet, apenas lo coloqué y esperemos sirva. No ha vuelto a salir el error P0421, lo usaré regularmente.

I think the Cataclean did help. The fuel economy has improved and so far so good no error message has re-appeared appeared.

Great packaging and great communication. Thank you.

Muy buen producto cumple con lo que se promete en menos de 24 horas se quito el error del carro por culpa del catalizador se borro solo 100% recomendado "APROBADO POR CHAYANNE"

My car get the P0420 every week after clearing it with my OBD reader than I read some good reviews of this cataclean and I don't believe a single 16oz will fixed the problem so I decided to buy the 5 litres bottle instead. Poured 500ml into my tank at 1/4full (15 litres) as instructed and instead of just 15 mins drive, I drove my car for a few days to almost empty and fill it up to full tank. Is has been 2 weeks (800km) and no Check engine light so far. It is way more economical buying the 5L bottle and I intend to repeat the cleaning process every oil change.