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

Very effective! At first, my car’s performance felt noticeably sluggish, but after using this product a few times, it helped clear out the exhaust system a bit. The power and gear shifts have become noticeably smoother. Highly recommended — it’s a bit pricey, but definitely worth it.

works great. engine runs smoother. little better gas mileage. check engine light gone,

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 got my year2000 lexus es300 check engine light (CEL) on and code is P0420, the car got 185K miles already, my inspection is coming, What I do? change a OEM catalyst converter cost me $2000. Check amazon reviews, I got this one and poured it in base on instruction. Did not work for the first 10 miles with 1/4 tank, CEL back again. After refilled the gas tank, I deleted the CEL but it back on again after 50 miles, I deleted again then it back after 100 miles. I gave up and even want to buy all parts(O2 sensors and catalyst converter), but finally it works after 150 miles, Code P0420 are gone and CEL never back on. I went to MVC and Passed inspection, Binggo! Now it is more than 200 miles and still no light on.I am so happy with this product, it is not just clear the CEL, also clear the whole fuel systems, make my car runs so smoothly. I had rough idle, it make it much better now. Gas milage is better too and engine is so smooth now, like new one.I highly recommend this one and will use it again for another few months.--------------------------------------------------------------------------------Update: After I passed the inspection and drove about 300 miles, the CEL back again, it did not really fix the CAT issue but it does help me get passed the inspection. Before, the CEL back on only in 20-30 miles, now, hundreds miles. I reduced it to 4 star since it did not help to fix the CAT problem permanently, but it did help me passed the inspection, which is much more value than $25. so for me, it is still worth to buy and try.---------------------------------------------------------------------------------Update2: I fixed the P0420 issue, it is due to bad O2 downstream sensor,. I just replaced the down sensor for $50 (part)+ $50(labor), it fixed all, P0420 code are gone, so it is not CatClean not working but O2 sensor issue. you are not expecting Catclean can fix O2 sensor electronic issue, but it did make my idle very smooth and make the CEL on delayed, so I still bring it back to 5 Star. Hope this feedback can help others who can not cleanup code with CatClean. If your code not disappear, mostly O2 sensor issue or Cat leaking something....