Really do what? use seafoam? Yes.. It does a great job of cleaning out the carbon buildup. I like using through the PCV valve since the opening in the intake manifold seems to get clogged with carbon buildup if you have tired rings. If it get clogged, you loose vacuum to your PCV valve which could cause oil to get in oil cleaner..which causing oil to get sucked in to the smog pump..which causing smog pump to go out...which happened to me.missyc said:do you guys really do that????