I recently got a standard 07 Cobalt LT. I love the car as it's just sporty enough to not be a mom mobile but great on gas. I've noticed over the three days I've had it that while I'm cruising it has like a hiccup moment where it feels like the back end is bouncing. Almost like dumping the clutch at too low or too high rpm or stomping on the gas after getting it in gear and letting off the throttle fully. I've tried slowing my shifts down some and it seems to help until I'm just cruising. Today I was rolling along at about 70-75 and it's lost all throttle response in 5th. I pulled it into neutral and gave it a few sharp revs and it picked up no problem. Put it back in 5th and it ran like it should. I was just wondering what the problem might be on the cheaper end of the spectrum. I'm gong to be checking plugs, coil packs, fuel filter, air filter, etc. tomorrow. Any help would be greatly appreciated. I've never had a car have this issue so it has me fully stumped as it's not throwing any codes and normally runs great.