Maybe I didn't search well enough, but I was very surprised at how little I found in the way of discussions here about intake valve deposits and cleaning. Seems this topic comes up frequently in the context of GDI type engines. Has this been shown to be much of an issue on these Eco's? If so, what is everyones favorite way to address it? I'm not trying to look for a solution without a problem but the two products I've seen recommended are CRC intake valve cleaner and Amsoil Power Foam...