Cavalier 98 automatic transmission problem

I would be appreciated by his advice, my Cavalier 98 hit when he executes the change from first at second speed and the rest of the changes with less blow, that is, does not grab the speeds gently with the delicacy with which these cars do it normally ... I have already taken it several times to the mechanic, the scan has been made, it says that they are sensors, it is changed and the fault continues ... they would have some guidance ...