


🛠️ Clean smarter, drive cleaner — don’t let engine troubles slow your hustle!
LIQUI MOLY 8931 Catalytic-System Cleaner is a 300ml specialized additive spray that effectively removes deposits and impurities from your vehicle’s catalytic converter and intake system. Trusted by thousands, it helps turn off check engine lights and pass emissions tests, extending catalytic converter life and saving you costly repairs.
| ASIN | B00XBOFZK2 |
| Best Sellers Rank | #19,843 in Automotive ( See Top 100 in Automotive ) #43 in Fuel System Cleaners |
| Brand | Liqui Moly |
| Customer Reviews | 4.2 4.2 out of 5 stars (2,333) |
| Date First Available | July 30, 2017 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 10.6 ounces |
| Item model number | 08931 |
| Manufacturer | LIQUI MOLY |
| Manufacturer Part Number | 8931 |
| Model | 4100420089312 |
| Rim Diameter | 300 Millimeters |
| Safety Rating | Não aplicável |
| Special Features | Chlorine Reduction |
G**G
Catalytic convertor cleaner...worked!
This item works! Check engine light is off in both my 2012 Jeep liberty and my 2005 Nissan...and have stayed out for 6 months and havent come back on every few weeks like they were both doing. Both passed smog with no problem after driving around for only 35 miles...... . check engine light went out. Mechanic wanted 1600 bucks to change cat in my Jeep. Finally I feel we got something for our mony!
M**X
Excellent quality, but be ready to work a bit
This worked great to keep the catalytic converter warning light off for several months. Be aware that it has to be sprayed into the air intake with a spray bottle, not just poured into your gas tank. It has to be sprayed into the intake downstream from the oxygen sensor, while the engine is warmed up, and with a helper keeping the rpms revved up while the first person sprays it in.
R**Y
Need a sprayer
Used in a 2012 Prius with almost 300,000 miles, the cat below threshold DTC light was coming on. I put this through the hose from the valve cover before the throttle body with a small pump up sprayer I got at the hardware store, while it did look like it was cleaning gunk out of the cat it did not solve the problem, the light continued to come back on with the same error code. I took the car to Toyota and they are in the process of installing the 2 new cats they said it needed, about $2,500 here in California. I also used it in a 2003 Chevrolet Tracker 2.0L with about 85,000 miles and no CEL. I was able to use some clear tubing to hook it up to a plugged vacuum fitting after the throttle body, I did not see anything coming out of the exhaust but the car seems to have better acceleration. I bought 3 bottles and poured all 3 in the sprayer. Still have some left for next time. Seems like a good product though not always a cure all.
J**L
Might work...it's worth a shot!
I'm generally very skeptical of automotive additives and research everything to death. The general consensus on catalytic cleaners was that they don't work. My 2017 Expedition threw a code for P0430, which indicates the Bank 2 catalytic converter is not functioning properly. Swapping in a new O2 sensor did not work. My next option was to replace the catalytic converter. On a lark, I decided to try this product. I figured if it didn't work, I was only out $16. I have software that reads information from the vehicle, so I can see what numbers the catalytic converters were generating on each side. Surprisingly, after one application, the numbers improved enough for me to pass my emissions test. I was prepared to be told it failed because I was unsure what the threshold for passing was. But instead it passed and the check engine light has stayed off for the past several hundred miles. I deducted one star because Liquid Moly has another very similar product that is added to the gas tank, while product this must be sprayed into the air intake. I accidentally purchased that other product first because the product packaging is too similar and use instructions can be confusing.
C**Z
Money to the trash
It doesn't work by itself, it requires at least two person and a special pump spray bottle that costs $68+, and that information is not written on the description of the product. Worst: it isn't eligible for return, so you get a decorative can.
J**N
Did the job
It works
J**R
Requires specialized application
I was hoping this would help clear a partially clogged catalytic converter that kept setting off codes in my Chevy Malibu. After reading the application instructions and viewing an application video, I realized this is intended for race cars - or at least that’s what they showed, and requires as specialized mixing bottle to atomize the material before getting sucked in through a vacuum port. One source on the Mfg’s web site said you could put it in a spray bottle and apply a fine atomized mist through the throttle body intake of a vehicle. I attempted that with limited success (having to disconnect my Mass Air Flow sensor - before starting the car - and spraying it into the air intake housing). I tried to rev the engine while spraying the contents into the air intake, but I think most of the content just puddled somewhere. I was hoping for some sign of it working while spraying but didn’t see any. Then I buttoned everything back up and took the car for a ride and produced a HUGE black cloud of exhaust in the first 50 feet of travel. I then heavily accelerated hoping to push all the cleaner through the system but think it was a quick one-shot deal at the beginning only. It may have done some good because my trouble code hasn’t returned yet, but it usually takes several weeks of driving to see it return after clearing. I doubt I properly applied the product, but also don’t think it is reasonable for the average Joe to be able to properly apply this product, so am not scoring it very highly in this review. Maybe someone else could get much better results.
M**G
Definitely a cheaper alternative to replacing the catalytic converters.
My daughter owns a 2012 Nissan Xterra. When it had about 175,000 miles it threw a P0420 code indicating a failing cat. Our mechanic quoted $3,600 to replace all 4 cats. That wasn't happening. I stumbled upon this Liqui Moly Catalytic System Cleaner and figured even if it doesn't work well, I'm only out $16. I powered the cleaner into the gas tank instead of spraying it into the intake as recommended. I cleared the CEL and tried the cleaner. The code did not come back on. She or I put a can into the gas take once every 3 or 4 months. We have been using it for the last 20,000 miles and over 18 months. Still running the original cats. I think we've put the cleaner in maybe 5 times since the CEL first came on. $90 over the last 18 months is definitely better than spending a few grand for new that will probably only last a few years.
J**A
Lo compré porque se prendió el código 0420 lo apliqué en el cuerpo de aceleración borré el código ye tiene 3 semanas y no ha vuelto a parecer el código si vuelve a marcar el código modifico mi reseña
M**G
جيد
Ü**R
Fena degil Etkisi oldu
A**Y
This product is amazing and does the job well. I opened the can and pore the content in a spray can. It's the spray can used by a barber. I opened the air pipe between the turbo charger and the airbox. The engine should be at its normal operational temperature. The engine RPM was maintained at 1500rpm. I gave a small burst of 2 sprays at a time in the turbo. Please note the engine RPM goes up after spraying. Once it comes to 1500, spray again. Do this till you spray 50% of the spray can. Keep the remaining 50% for the next time or you may put that in the fuel tank. There was a noticable reduction in the smoke coming from the exhaust even at 4000RPM. This product definately works. Improvement observed after doing the process. Engine runs very smooth and accleration has gone up. The accelerator feels very light. I used it on my Ford Aspire diesel as it was giving some black smoke. I am very happy after using this product. Please follow the same process for petrol vehicles too.
A**Z
eficaz, utilizar con combustible premium, solo medio deposito por bote, circular por autopista en una velocidad mas corta, a unas 3000 rpm
Trustpilot
1 month ago
1 month ago