GUARANTEED TO PASS EMISS.

I added this to my fuel and it shut off the engine icon on the dashboard for a few days. The light has since came back on so I may need another treatment. Time will tell.

My 2005 Jetta failed the inspection and my mechanic said (after clearing the engine light) that I should drive the car for 20 min highway and 20 local. We've tried that the whole day but out of three lights on his device only 1 went away. Next day the light engine came back. After not being happy with the explanation offered by him (a family friend) that I should keep driving it until we get lucky I went online and found CRC 05063. Followed the instruction (one bottle on full tank of gas). Before my tank was under 3/4, engine light went off!! At half tank I went and did the inspection - IT PASSED! I am really impressed! Update August 2015! I have been using this product for 2-3 years now and if it is not working for you please read. In July I have used the first bottle and took my 2005 Jetta for inspection. It failed. Ordered a second bottle and it failed again. My mechanic said keep driving. Did 200 miles in one day and nothing. Decided to take matters in my own hands and ordered Autel MaxiScan MS300 ($18, it allows you to read and delete codes). There were two faults - EVAP and 2nd something about Oxygen. Went online and this is the first time I heard about driving cycles. These are steps that you have to follow so that your car's computer can start measuring all the parameters needed for the test. Driving cycles are not exact science but I tried to follow the instructions as much as I could and after just 20 minutes (10min city and 10min highway) ALL the parameters were set and I passed the emission test with flying colors! So, just before you give a comment about CRC like "tried and didn't work" be aware that there are other things you have to take into account.

The engine check light disappeared for two days and came back. Before every time I reset the error code the engine check light would not come back before few days, but after using this product the it would come back next drive.

A fruend called me anout her MIL/Enginel light coming on. P0 420 came on i think. O2 sensor bank 1. Exhaust had good pressure so catalytiv wasnt plugged up. So bought some of this and her light went out i assume bevause she said its ok (shes vietnamese with not the best English) and hasnt mentioned it in last 3 weeks. I bought a few more to give her some for next time when needed and for my 09 small truck.

It has worked every time I've used this product. Won't fix a damage catalytic converter but will help you pass the test if your car almost passed.