heavy take offs on 1998 Ford F-150

heavy take offs

the truck shifts smooth
good oil levels
change brakes
change oxygen sensors

Asked by for the 1998 Ford F-150
What do you mean by "heavy take offs"? Wouldn't have expected brakes or oxygen sensors to improve a symptom described as a heavy take-off. Do you hear a noise, like a mechanical problem? Or do you feel a "slam" on the initial acceleration from a stop? Need more info. Thanks!