When I'm on the highway doing 65 and accelerate lightly my boost gauge will go from 0 to 10 in hg back to 0 over and over again and it causes the whole car to shudder. What could be the cause of this?
2009 Cobalt SS

 

Down shift. To much load for the rpm and the car is going oh you want power, wait not that much, oh more power, oh wait not that much, oh more power, etc. etc. etc.

 

I would think that's the case to except for the fact that it started out of nowhere. I never I until 3 months ago.

 

Then do a boost leak.