Transmission issues

When you engage the drive gear mode the car cannot move unless you accelerate harder as it moves slowly and then engages next gear and moves smoothly there after. On a hill once you stop you can never move from that sport because it doesn't engage the first gear. In the dashboard it doesn't show the D signal but will show for others like N and R.

This issue happened all of a sudden.I discovered latter that the plastic pipe from the air sensor was not placed back properly to the Throttle and there was leakage. That was corrected but noticed it could have affected the TPS. Would that cause the gear problem too.