Hello Delatorre.. I was experiencing shiftting problems similar to yours.. A cadillac mechanic i know told me to change the Vehicle Speed Sensor also know as the VSS.. I changed the sensor and have'nt experienced those problems in months.. Its a cheap part.. only like $30 or so.. Its worth a shot.. Also my check engine light was not on.. No code at all for the VSS came up in the current or history codes.. So there dont have to be codes for it.. I just took a gamble and it worked out.. Good luck..