62 Posts. Discussion Starter · #1 · Sep 4, 2007. Hello, everyone! I have been getting ready to replace all the fuel injector seals on my 560SL and 420SEL. I purchased an ultrasonic cleaner and cleaned the 560SL injectors in it using SeaFoam as a solvent. It seemed to work very well, indeed. I am ordering the injector "Insulators" (the "cups. Honda fuel injectors can be cleaned in several different ways depending on the severity of the problem, your type of vehicle, and the particular equipment your service facility uses. ... "on the car" cleaning process where special equipment is hooked up to the fuel intake and a powerful solvent is injected under high pressure through the fuel.