I washed the engine compartment on my03 Chevy Silverado 1500, and after that a msg appeared on the cluster "REDUCED ENGINE POWER" plus check engine light is on, and I can balery keep it on, if I let the gas go, it will shut down, any ideas of what may be wet?

 

Take an air compressor hose and blow off everything. Don't unplug anything, but look for plugs that might have come unpluged. Is the truck clattering under acceleration? The knock sensors could have gotten wet which I believe is a common problem. On the back side of the intake there are 3 wires.1 leads to a plug right behind and underneath the rear of the intake manifold. Make sure it is pluged up. When I pulled the foam insulator out of the backside of the intake on a friends truckI accidently unpluged that plug and the same message popped up and it clattered pretty rough and his gas mileage went to hell. It was the crank or cam sensor code. Have you had the check engine light code read yet?