...What could be wrong? I have a Hyundai Sonata 2004 and when you first start up the car after letting it sit all night everything fine. No ignition problems but once you put it in drive and apply the gas the car kinda shutters to go like its trying not too. It's even jerked a little and hesitated to a stop and wouldnt continue even though the engine sounded like it was running fine. It's almost as if its having trouble getting into gear. Once it overcomes the jerking and hesitating however, it runs fine. What could be wrong? And it's still under powertrain warranty, would it be covered?