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Re: 99 Silverado 4.8L P0300 Misfire and Knocking
Posted to Technical Discussion Forum on 5/24/2003

Hello Brian

This may seem way out there, but it may have water in the intake manifold. If it does the water is comming from the EVAP vent sol. The sol. is mounted under the truck between the cab and bed. This evap. system pulls vacuum all the time when its n... Login to read more.