05 Sonata 2.7 rough month help please

I took the car the Aamco thought the car a had a trans problem. Very noisy sounded like trans was screaming to me. When driving down the road it accelerates fine but when it reaches cruising speed it is like the car looses all power coasts to 20 or so mph then surges all while my foot stays steady on the gas pedal sometimes even feels like someone stomps on the brake then surges. Aamco says trans is fine wheel bearings front axle bad. replaced those. Check engine light came on after car died while driving down the street crank shaft position sensor bad replaced that. Can't figure out what would cause the loss of power when at cruising speed then surge. I have cleaned out the throttle body suggestion from Dealer. Through a dart at it and replace the throttle position sensor it did not help. The check engine light is not coming on and I don't think it is safe to drive. when engine gets warm some times even have to feather throttle to get car going from stop sign please any suggestions would be great hopefully something cheap and stupid.

Thank you,

Craig

 

Have you tested the : Engine Idle Air Control?
I know it sounds like all it does is adjust idle, but it can adjust engine speed also.