Quick question guys, I was just at NJMP this weekend and noticed that on the inside of my exhaust tips there was a white/grayish color. Now i"ve seen that when I use 100octane but don't remember seeing it with 93octane. The only mods I have is suspension and exhaust. The car has never been flashed. The car ran Great! has this happened to anyone? should I be concerned? is she running lean?

Adrian