Great product for intake manifold maintenance on GDI engines. Only improvement would be an applicator like the Berryman's intake cleaner kit has.

Just used it on my car and I'm hoping it works. Car is at 100K miles first time ever using this type of product. After it was done heat soaking for an hour I went to drive it and it started smoking a lot and engine knocking then the car turned off on its own. Started it back up and it ran like normal so I'm hoping that was just a bunch of carbon buildup being burned off.

I have an older car, 1 1994 probe gt and had my intake manifold off in order to do valve cover gaskets...Since the intake was off ,I noticed a Large amount of sludgey buildup and some carbon on the intake runners and on the engine itself, the intake valve ports were sludgey and the valves themselves had moderate buildup..This car has 250,000 mi and this kind of cleaning has Never been done b4 on it..I made sure the valves were closed and sprayed only a small amount of the cleaner, enough to cover bottom of valves..I did Not fill up each port.. I then used a simple tooth brush and scrubbed the port and valve.. this CRC stuff kinds instantly dissolves varnish and sludge..I Did prescrape off the heaviest deposits in each port B4 spraying...what I noticed is it reacts favorably and quickly with buildup and just melts it..if u add a little work with the toothbrush as well, I was able to get pretty clean ports and valves were deposit free..Now I dont have a GDI car and from pics ive seen, the buildup that occurs there is really aweful, worse than mine for sure...However, this CRC seems useful to dissolve valve buildup thats in a sludgey state, mine wasnt carbonized hard but the softer type.. its also good for throttlebody and intake manifold cleaning...actually when I had manifold off, I sprayed it inside with brake cleaner which also works well, however I was concerned about daring to use it on the valves for fear of damaging the valve seals, thus I sprung for the CRC which is known safe..I dont know how well it would work on GDI cars sprayed into a vaccum hose while car is running? but if you are able to apply it directly to the valves let it soak a few mins, use a toothbrush, then I wet vacced it outta there and wiped the port and valve squeaky clean...it works That way.,.

Idk much about this product. My husband does! It was a great money value, for my husband it was easy to use understand! Helped car run better longer! Good mileage

I bought 4 cans since I have 4 cars in the family. I used it 1st on daughters 2015 beetle which has 75k miles but still runs great she noticed a slight drop in fuel economy. I removed the MAP sprayed in that port car ran erratically since I didn't unplug the MAP. I did get a some white smoke at tailpipe, after 1 hr hot soak drove it for 20 mins didn't really see any smoke at the tail pipe but car ran fine it did seem to be more responsive. The next day I changed the oil, filter spark plugs. The plugs seems clean not much deposits, forgot to take pics of the plugs.On the 2006 Toyota Avalon the car is port injected I add Berryman B12 every 3 months so it's always run great. It has 145k mile at 90k I had the engine pulled out to replace gaskets, VVT supply line with new steel line, spark plugs, drive belts, water pump, engine mounts and host of other wear items. So it's well maintained, I was hoping this product would get fuel economy back to 32 mpg like 3 yrs ago, but so far no change.Overall I believe this is a good product for GDI poorly maintained port injection cars

Will see

You can feel the difference. It feels a little rough on the car when you take it out for the 10 min spirited drive. You will see smoke out of the exhaust during the drive, then it clears up and the car starts to get more hrspwrs. But seriously its a good product and it works.

I use this cleaner before every oil change. First time I used it produced the giant cloud of smoke from the muffler. I still get smoke, just a lot less now that I am using it regularly. I find it helps with my gas mileage.

This stuff works great. It's a little spendy in my opinion and it's easy to go through it quick, but it works great at cleaning parts and breaking down carbon build up. I used it for valve cleaning in my BMW 335i with the N54. Anyone that knows this platform knows how bad the valves can get! This cleaner breaks it down quickly making it an easy job.

Good price. Got it quick. Haven't used otnyet but I keep getting annemail to rate it.

My car definitely seems to run more smoothly after I us this. I use it between every 5 and 10 thousand miles as routine maintenance. I hope it helps keep Carbon build up down.

Followed directions, no trouble codes car still runs fine. No way to tell if it worked unless you get a mini cam down intake.

My 2013 Hyundai Accent was having some minor sputtering issues. My mechanica mentioned the GDI carbon buildup problem and offered to clean it out for several hundred dollars. I like my mechanic, but they are a national chain and have sales goals. After doing some reading and youtube watching, I purchased the can and used it. Now the sputtering is gone. Granted it is not as good a job as my mechanic would have done, but for the price difference I am happy.One issue I ran into was that my engine would not stay at a set RPM. I followed the instructions the best I could, but the initial drive out my engine lost power, a ton of smoke came out the tail pipe, and I heard some terrible metal rattling. Afterwards the car ran great and is still going strong. Not sure if this is because I did something wrong, large amount of carbon broke off and went through the system, or my car has other issues that I made worse. Time will tell.

I will give this product a negative stars it were possible. My husband used this in my 2015 Kia Optima and it basically shut the car down. It was so bad I had to have the car towed to the shop. AVOID this product!!

This stuff does work and it works well. But if you have a GDI engine and it's clogged up really good with carbon it's gonna take using this every thousand miles for like four or five cycles before it clears up the idle completely. I do recommend this product tho. IT's not bs and imo it does out perform seafoam. Seafoam might be a bit safer for use tho. This stuff packs a punch and you have to be careful how much you use it or you vehicle will run a bit weird. I'd say use it every thousand miles to clean you engine thoroughly and then every oil change. Not the every 10k miles they recommend. But more like eery 5 to 7000 miles.

It seemed like it worked from the smoke coming out of the exhaust. Couldn't see the valves but hoped it did good probably do it again several months later in the summer for the engine for heat