Just a few days ago, on the advice of a work colleague, I put Liqui Moly’s injection cleaner into the tank because my Cali occasionally stuttered in the speed cellar. The problem was already solved next day. The engine no longer stutters at all as I know it. I then turned out the candles yesterday to look at what they look like and saw spark plugs with a reddish insulator and an equally reddish mass electrode for the first time. The rest looks like imm he. Has anyone ever had such experiences? Where does the color come from? The injection cleaner is yellowish and clear. Like apple juice. Hope you can see it to some extent.