why is my avalanche got to 10 m 30 with the gas allwaydown &the dash shows engine reduce power whats rowng with it

Enrique - For me, I had a series of engine codes that AutoZone or Advanced AutoParts identified for me; one of which was a Transmission code (posted here - http://www.cargurus.com/Cars/Discussion-t34307_ds615332). After a few hours of work, one of our local mechanics was able to determine that it was a transmission sensor that went bad. As a result, my truck went from driving like normal to limited power. As you described, my accelerator hit the floorboard, but I was lucky to make 30 - 40 mph on the highway. There are some CarGuru tips in my post, which might be helpful - for me, the sensor needed to be replaced and now it works fine. HTH; Good Luck!! :)