I use a product called k100 which you add directly to your tank. It works well for keeping everyone clean. I have a carbed vector (2006) which was sputtering when it idled, because she sat all the time. The previous owner put 500 miles on in the past 6 years! I ran some k100 through and the sputtering toned itself down quite a bit. Seafood just didn't do as good of a job I noticed.