Took apart injectors on a 97 lesabre with 100k on it a few months ago; never had any FI cleaner ran through them. They looked pristine and the pattern looked great. I would only use a FI cleaner in certain, special applications, like manually (dissembling) cleaning gummed up injectors, carbs, etc. Don't think it does much running it through a tank of gas with all the other cleaners in quality gasoline.