This product is freakin amazing. Ignore the negative reviews, those are people who have no clue. I ran one can through my 2012 Jeep Liberty V6 that was getting 12-16MPG and had poor pedal response and no acceleration. I had put plugs and wires, air filter because we just bought it for my daughter and it had 118k miles on it. We took compression test and it was fine. Narrowed it down to possible carbon buildup. Well CARBON BUILDUP INDEED! This thing smoked during the entire can during idle and almost none when driving. Immediate increase in acceleration. Fuel mileage restored to 15-19MPG, which for 118k miles is good enough! I felt the car had more to give so today (a week after the first can) I ran a second can through. This time it did not smoke during idle, but on the road test it burped quite a bit of smoke and the check engine lite came on and went off. no big deal. I was right, she did have more to give! I got MORE acceleration the 2nd time! At the time of writing this, I did not have the mileage into it to retest the MPG, but I will this weekend. I suspect 16-20MPG now. FREAKIN AMAZING STUFF for under $40! NO brainer!

I also ran a can through my son's 2014 Chevy Sonic 4cyl (68k miles) and it did not smoke at idle. During the road test, It was sputtering badly to the point I had to use manual shift to rev up the RPM's. Check engine lite blinking. I stopped, let the engine recover and pulled out onto the main road. It started to accelerate and then almost died. I lost all power momentarily. Then this Hiroshima cloud came out the tailpipe, HOLY CRAP WAS THAT A MASSIVE DENSE CLOUD! Afte that, it cleared up and once again, we got the same results, much better acceleration and a 2.4MPG increase, it now gets 29MPG city! (prior was 26.6MPG).

I ordered 2 more cans to run through my 2012 Silverado with 788K and my wife's 2017 wrangler with 50k.

These cans are worth the investment, you immediately get it back and then some in recaptured MPG, let alone the better performance factor.

I own a 1999 tahoe with high miles.
I put alot of work into this truck to get it to run damn good. I used this product because seaform couldn't get it to smoke in which let's you know the product could be working.
Berryman wow! Right off the jump my truck smoked up the block and a very bad smell came from the exhaust.
But the test was afterwards when I went for a drive. Big big difference. No complaints! This product works no BS! I don't care what anybody says. Berryman is the business. Carbon build up nomore. Trucks runs way much better performance top notch 👌

My car went from frequent part throttle misfires to just some stuttering and an occasional misfire. If your intake valves are as far gone as mine it's only going to do so much in one bottle, but it's definitely worth trying. I'll throw a second bottle at it and if it smooths it out even more maybe I'll just run a can every couple of oil changes.

I've got a 2018 Silverado with 4.3L and 56k miles. This along with wife's 2013 Pilot, 130k, and an ancient 1990 Ford Bronco have never been de-carborized, so I bought three cans. Did this on the silverado and was about as easy as you could ask...literally, disconnect the air plenum, stick in the hose, start the engine and press the button on can. My truck never stumbled with the chemical. Let it hot soak 30 minutes and took it on a 15 minute run as directions indicate. It did throw a check engine light that disappeared less than 1 mile into the trip, and the truck is running smoother. There are plenty of chemicals out there for this procedure and this is the mid-priced one. I've seen others that have the same active ingredient but less fancy application kit for as low as $12. I'll probably try one of those if I do this again.

This is my first amazon review and i am only writing it because this turned on my 2022 Kia Carnival's check engine light. So if you have a scan tool capable of clearing your vehicle trouble codes dont worry, but if you don't the parts store will refuse to do it, and i can imagine if I were to bring in my brand new kia with 10k miles on it to the dealership and tell them I used a valve cleaner on it. Maybe nothing, maybe them trying to "void my warranty" ?? It was a random cylinder misfire code that I just reset at home but I have a scan tool and im not too worried that this product would actually harm anything. Does it work? I dont know I didn't look into the intake ports on my basically brand new GDI kia to tell how much if any carbon was there and I have no way of knowing what the piston rings look like without removing them from the block. Would I continue to use this to keep the carbon from building up on my GDI kia, Absolutely! I believe this works, i've seen evidence on YouTube thatleads me to believe it does something to clean up the nasty places that can develop. I know that carbon buildup can cause failures, and problems that I dont want. Im only giving it 4 stars because of the CEL and im only writing this review because I feel like people need a heads up. Should you buy this for your direct injection engine? Well it's super easy to use, watch the manufacturer instructional video on YouTube (search the product) and you are ready to go. It's kinda pricey but the ease of use makes it worth it. If it's an ounce of prevention, it is better than a pound of cure. I preformed this before an oil change at 10k miles and plan on preforming the service every 10k miles and am hoping for the best as we plan on keeping the Carnival for 10 years or so. Cheers!