air filter is a brand new.i have never checked maf sensors.throtile body is good.it openes and closes with no problem .the problem happens only after 80mph .it wont go any faster if i wont floor the gas pedal(that way it downshifts gains some speed and then goes fine).Also no check engine light is on. No codes. My mechanic checked it with the computer and sad that car has no problems but that is not true. After 80 car would start acting wierd like running out of gas and if i press gas pedal more the problem is getting even worse and if i floor it the no problem it starts to downshift and gains up to 90 mph with np.