CRC Guaranteed to Pass Emissions Test Formula, 12 Fluid Ounce

Failed emissions because "Oxides of Nitrogen" was slightly too high. Bought this on friend's suggestion. Followed the directions EXACTLY. I used premium 91 gas also. Then PASSED EMISSIONS the 2nd time! IT WORKS!

Good product put a bottle in my gas tank and after twenty miles the check engine light went out for thelr catalytic converter when I can afford to buyore I will thanks very much

My 1997 Chevrolet Venture minivan failed the California smog test for the first time due to high NOx emissions. Doing a search on the internet I found the likely causes to be a clogged or sticky EGR valve, upstream O2 sensor and carboned combustion chambers. The EGR valve and upstream O2 sensor are both the original parts so I cleaned the EGR valve which was a little sticky and replaced the upstream O2 sensor. Lastly, I added a bottle of CRC Emissions Test Formula to the gas tank when it was half full and followed the rest of the instructions on the box. Passed the retest with NOx reduced by 50% from the original readings and HC also reduced. Not sure what the main contributor was in getting a pass for the 2nd smog test but I think a bottle of the CRC Formula was worth it as an added measure especially considering CRC's double your money back guarantee.

I have an 03 Corolla. Just this year my check engine light popped up. Code p0420. I wanted to try this product just because I didn’t want to spend money on a new cat. This product does advertise that it’ll pass smog and help with a p0420 code. From the reviews it looks like most people were happy with the outcome. Others had no luck. I wasn’t sure myself. Anyways, I followed the directions on the box. And it passed! It also claims to improve performance and I agree, I think my car’s performance did improve. I don’t think it’s the proper/permanent fix to a p0420, but it helped me pass smog.

I really works. Dealership total me I needed a new catalytic converter. After 2 uses per directions, no sign of converter issues

Very good item to help pass SMOG test. Car passed first time with no issues.

I started getting P0420 codes on my truck at around 180k miles. I thought I'd try this product to see if it would clean the cats enough to buy me some time before having to pay the big bucks to replace them. At first, I only bought a single bottle, not realizing that I needed two since I have a twenty gallon tank. I decided to try adding the bottle to a half tank of gas to see if worked. This appeared had no effect and I still got the CEL light coming on after.Rather than write this off because I might have used it improperly, I bought two more bottles at a local auto parts store and followed the directions as recommended. This time, I added both bottles to a full tank and ran it until the fuel light came on. I refilled the tank and cleared the code. This time, I was able to go through about three quarters of the tank before the code re-appeared.So my semi-unscientific conclusion is this: This stuff probably works temporarily so will allow you to pass the emissions test (hence the name) but doesn't have any long-term effect on the state of the catalytic converters. If you're serious about maintaining your car's emission system and not just trying to pass the test, this won't help.

"Miracles in a bottle" can be dubious but where I live, with ever tightening Emission specs, stuff like this can't hurt. The specs for my '99 Tahoe have tightened twice since acquiring the vehicle in June of 2003. I have saved all the test results since the first one that was done.