LIQUI Moly 8931 Catalytic-System Cleaner, uncoloured

Get a spray bottle from Home Depot.unplug mass airflow sensor. (The engine will stall if you don’t) remove the hose to get access to the intake. Have someone rev to 300 rpm. Spray the whole bottle. It takes about 5 mins. Reinstall the mass sensor. Clear all the codes.Go drive 30 mins in highway speed. Go to inspection if no light comes on. Good luck

Car good

Impresionante luego de 250 millas mi luz de motor se apago

I got code 0420. Tried different product that you put into gas tank. Code came up soon and it didn't seem to work. This time used this product and it lasted for 250mi. I'll give it one more try and write an update here. Update: second time worked for 120mi. Unfortunately, my code 0420 wasn't solved. UPDATE: after the second bottle it took me 150mi before the code 0420 appeared. Unfortunately it didn't work for me. My car has 208,000, but I changed cat two years ago, so hopefully it's something else.

Excelente profucto

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.

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.

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!