royal purple & seafoam spray together clean intake valves on a gdi direct injection marvel along with crc intake valve cleaner. plus many others to take on a direct injection or gdi. also scotty Kilmer the truth about marvel mystery oil for your car is a great video the truth and project farm seafoam vs marvel mystery oil! the ultimate showdown! is another great video so be sure to watch those videos.well sea foam motor treatment and seafoam intake cleaning with other subscribers choices chose by you for you vs intake valves with alot of carbon build up also known as valve gunk. to name a few crc intake valve and turbo cleaner, seafoam spray, royal purple max blast intake valve cleaner, marvel mystery oil, gumout, lucas complete fuel system cleaner and so much more remember just subscribe and comment telling me what you want to see tested and how to test so we can fin the best intake valve cleaner or how to clean intake valves here at the nates interactive auto community NIA. so this may help a poor idle or hesitation , even rough ide by using a fuel treatment or fuel additives, so try these products and tell us what gas treatment works best and what gas additives you have used. with carbon build up thats correct carbon buildup. sea foam is tested thoroughly. also stp and gumout direct injection cleaner, we also test stp fuel treatment along with so much more and as always thanks for watching.