Cataclean Fuel & Exhaust System Cleaner – Pass Emissions Tests – Clear Check Engine Lights – Restores Catalytic Converters, DPF Filters and Cleans Fuel Systems, 16oz - Pack of 2, (120019)

I own a 2006 Nissan Armada V8 with over 180K miles on it. A "Service Engine Soon" message appeared on the dash... code 420 (problem with catalytic converter). I could have taken it to a repair shop and paid them a $280 diagnostic fee and then potentially another $1800 to replace the catalytic converter, but I didn't want to put that much money into a vehicle this old.I decided to give Cataclean a try. The instructions said mix one 16 oz. bottle with every four gallons of gas in your tank. I bought a six-pack to mix with 24 gallons of gas (tank holds up to 28 gals). It took about a week to run that mix through the engine, after which I refilled with gas only. I could have cleared the code to see if it came back, but I decided to see if it would go away on its own first. In less than 2 weeks time, the "Service Engine Soon" message dissappeared and hasn't come back since.During that two weeks, I monitored my miles per gallon and found that I was now getting exactly 20% better mileage! There was also a noticable improvement in responsiveness and acceleration. I wasn't really expecting all that, but the fuel injectors were obviously in need of a good cleaning... and they obviously got it!Six bottles of Cataclean wasn't exactly cheap, but it was much less than the alternative. I'm very pleased with the results and can highly recommend it.

I highly recommend this... Had issues with my 2014 vehicle with very high miles. I had my car checked as well as the PS error code etc. Was told I needed a new catalytic converter. I tried this in desperation and in effort to avoid that cost. I tried it at 1/4 tank as described and also switched to ethanol free gas. That worked a miracle for me. After just one treatment my engine light turned off. I continue to use that gas and then did 2 more treatments over the year. (Generally every 4 -5 months.When I forgot the next time and the error code happened again, I did the treatment again, it cleared and as stated I've never used regular gas again.1.5 years later no issues, never changed the converter. So grateful!!!(My only concern /negative is the price of this stuff more than tripled! ) that's not good at all.

Here's the quick summary: Yes I used this and yes my car passed smog test.... but I would try lots of other things before using Cataclean again.My vehicle is a 2004 Toyota Sienna with 137,000 miles. Check engine light (CEL) has been on for two years now. The CEL is on due to the following codesP0420 - Cat Bank 1,P0430 - Cat Bank 2 ,P2238 - AF Sensor Circuit.This year we got the registration renewal and were required to get a smog certificate. Since you can't pass smog test with CEL on, we took the van to the dealer to see about getting it the CEL fixed. The dealer recommended replacing both catalytic converters the A/F sensor and calibrate ECM. All for a cost of over $2,800.So instead of spending the $2,800 I figured it was worth it to give Cataclean a try. I followed the directions and added the entire contents to about 1/4 tank of gas. Then immediately drove the van until it was empty. The van was not completely empty, but the yellow fuel warning light did come on and the gauge was on E. At this point I filled up the tank with premium gasoline. After filling it I immediately drove the van for about 40 miles. I was expecting the CEL to turn off but it did not.At this point my story gets less normal than most I suppose. My wife drives this van most times and I have another car. It just so happened that my wife was sick with a bad case of the flu and she did not drive the Sienna for more than 1 week. So the Sienna sat with nearly a full tank of fuel and whatever was left of the Cataclean for 1 week.After 1 week of sitting in the garage, I decided it was time to try to drive the van and see if the CEL would turn off. This is where it gets very weird and discouraging and expensive. I pulled out of the garage and the van barely ran at all. It felt like only half of the engine was running. The engine had very little power and to make matters worse the CEL was now flashing ON and OFF. I pulled over and did some quick research on my phone and found out that a flashing CEL is bad news. I spent the next 4 hours "babying" my car. I would drive it for a little bit and the CEL would flash. So I would pull over and let it idle next to the curb. When the engine was simply idling the CEL would not flash. I did this for hours and hours and the CEL flashing got less and less prevalent. Finally the CEL stopped flashing after about 4 hours of driving and idling. If this does happen to you, you need to be very careful. Driving with a flashing CEL could lead to really expensive damage and even your car catching on fire.After that long evening of babying my car, the CEL never flashed again. But the car did not run correctly after that either. The car was rough at idle and vibrated a lot while it ran. And now, my car had a new code P0354. I took it to a mechanic and he replaced the #6 ignition coil and spark plug and cleaned the fuel injection system. This made the car run smooth and cleared the P0354 code. Replacing the ignition coil spark plug and cleaning the fuel injection system cost $510.I had a lot of expensive problems after I put in the Cataclean (see above). These problems could have been a coincidence and I could have had those problems without the Cataclean. After all, it's an old vehicle with lots of problems. Anything is possible. But I don't think I will be using Cataclean again.I cleared all codes and tried to run the monitors. For those of you not familiar, there are "monitors" which run in software on your vehicle. These monitors must be run and passed with no codes before you can have your car smogged. If the monitors generate codes, then the CEL turns ON. If you clear the codes, your CEL does go off, but your monitors are now "imcomplete" in your cars OBD memory. You cannot pass smog with incomplete monitors (actually the number of incomplete monitors allowed to pass smog varies from state to state so check with your motor vehicle department). You can find the rules for California here: [...]So now my car runs smoothly, the Cataclean has run through the emission system and the CEL is off. I have two incomplete monitors. One of the incomplete monitors is the Catalytic Converter monitor. So I then drive the van around town running some errands. Mostly stop and go, but some highway driving. After about 50 miles the CEL turns ON and generates code P0420... very discouraging. But I did not give up. I cleared the P0420 code and decided to try nothing but highway driving at moderate speed. Just a hunch I guess. So I got on the freeway and drove. Entirely freeway driving at very moderate speed. I got in the slow lane with the trucks and probably averaged 55 MPH and for it's worth I turned my Air Conditioning off. I did this for about 75 miles. I kept checking the scanner to see if the monitor for the Catalytic Converter had run, but it said incomplete. I must have checked the scanner 30 times to see if the monitor had run. Then it happened, the Catalytic Converter monitor ran and the status went to OK with no code. As soon as the monitor ran with no code I found the first smog station I could find and got a smog certificate. YEAH!!!!In order to do all of this I needed an OBDII scanner with me in the car to check monitors, read codes and clear codes. I used a very inexpensive OBDII scanner that I bought at Wal-Mart for $21. I think some of the inexpensive models offered on Amazon would work as well. You don't need an expensive scanner to do this. The main thing for checking monitors is a feature called "I/M Readiness Status"-- make sure your scanner can do this function.So did the Cataclean help pass smog? Did Cataclean cause the damage to the ignition coil? Did not driving it for a week in the middle of this process cause a problem? .... I don't know. If I were to ever need to use Cataclean again, I would drive the vehicle... a lot and try to get it through the system as quickly as I could. Hopefully, I won't need to use it again.

I was skeptical that using this would make a big difference but it actually works. I have a 2004 Lincoln Navigator with 206K miles on it and was getting about 12 mpg on the highway and as little as 9 mpg around town. After treating the fuel as directed and using about 3/4 of a tank with Cataclean in it my highway gas mileage is now about 15 mpg. I haven't had enough time to see the difference in city driving but I haven't seen a number that good in the last 3 years that I've owned the car.