Under my hood i have a chirping sound. It does it when the truck shifts and when its decellerating. It quits when i give it gas. Could it be my Belt tensioner? I've heard that if you can move it by hand then its to loose, however i do have to bow up on it. Any ideas?

 

Sounds like a belt problem. Either the belt is worn out, got some oily fluid on it or you have an idler or pulley sticking. Take the belt off and check all of your accessories, idlers and tensioner. See if any are loose or sticking. Go ahead and replace the belt, it's cheap.