Here is the serpentine belt diagram for a 2006 Chevy Impala 2006 3.4L Engine.
To remove the belt, first start lifting or rotating the belt tensioner off the belt with 3/8 inch breaker bar. And then remove the belt and inspect the belt and the drive belt system thoroughly. When you do the inspection, check to make sure that the belt is aligned to the proper grooves of the accessory drive belt pulleys, also there are no dirt or debris remaining on it.
To replace with new belt, use same 3/8 inch breaker bar by lifting or rotating the belt tensioner and make sure that the belt is securely routed. And then check if the belot length scale on the belt tensioner to see if it has proper installed length.
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