what would cause the car to hesitate when taking off? on 2000 Audi A6 Quattro

recently purchased my 2000 audi a6 quattro 2.7. I installed both the upper and lower oil pan, new oil filer, oil cooler new everything. once the car was starter and attempted to be driven we discover that the car had no fluids at all and had been drained. we put 6 quarts of fluid. the car hesitates when i take off ant the check engine light stays on..code came up tcm 1423 1606 could this be due to lack of transmission fluid? it hesitates at first gear then takes off. please help

Asked by for the 2000 Audi A6 Quattro
typical german used car seek a diag and est these are known for problems after 50k miles or 5 yrs