I have a 2007 cobalt ss supercharged stage 3. I just recently replaced the belt tensioner and when i start accelerating my boost goes up to about 10psi and then drops to about 8 or 9psi. At first i thought it was because the belt is slipping so I tightened the tensioner a bit more and the problem is still happening. I read another forum saying it could be the bypass valve but I'm not entirely sure. Any input would be greatly appreciated.