Transmission shift problems can be caused by simple faults, such as a low fluid level, contaminated fluid, plugged filter in the pan,
bad shift solenoid (s), poor working PCS (Pressure Control Solenoid), faulty
throttle position sensor or speed
sensor, or dirty...
The lack of response to the accelerator pedal has quite a few potential causes that would have to be sorted out in a diagnostic including, just as a few examples, plugged fuel injectors, faulty oxygen
sensors, fuel pump and / or filter, vacuum leaks including that caused by a faulty EGR system, ignition system malfunctions,
bad valve timing if the timing belt or chain is worn or skipped, blocked exhaust (e.g., catalytic converter fails or becomes clogged), a faulty airflow
sensor or
throttle position sensor, and so forth.