I have been trying to narrow down an issue on my 2.4 LE5 cobalt SS where under hard acceleration there is a really nasty hesitation, as in, the RPM's are bouncing up and down violently as if the car is fighting to get through the gears. It records no misfires when this happens and zero knock retard, the only thing I've been able to come up with is cam angle errors generally under any condition, typically worse under hard throttle, seeing 10+ for error during hard accell. I dont really know what this issue could be related to other then the actual cam gear itself, however the car throws no check engine light for the cam angle being off.