2002 gmc envoy_slt
I am replacing my Cam Shaft position sensor and actuator solenoid. In doing so I noticed alot of sludge buildup. I have understood that using seafoam was the best bet, however there are no directions for use on the bottle. How much do I add, and where? I have seen people talking about adding strait into the oil, adding it through a vacuum line, and in the fuel. Recommendations please?