See also:

Steering Gear Box, Linkage & Boots/Lower Arm Ball Joint
With the vehicle stopped and engine off, check for excessive free-play in the steering wheel. Check the linkage for bends or damage. Check the dust boots and ball joints for deterioration, cracks, ...

Hybrid-ness
Before I get into the performance and technology aspects of what makes the Sonata Hybrid tick, I've got to point out the fact that the Sonata Hybrid looks dramatically different from its gasoline- ...

Spark plugs
Make sure to install new spark plugs of the correct heat range. ...