chillis

Hi all, I just got my 2001 a6 2.7t Quattro 6 speed a year ago, awesome car never had an issue until now. The car has 180k on it and is a 6 speed, 1st 2nd and third gear all work perfect but when in 4th 5th or 6th at around 2500rpm if I put the pedal to the floor to pass someone without shifting the car starts to have issues, feels the same as when a chain skips on a pedal bike. This is the only problem I have, when in higher rpm in those gears the cars has its normal great pick up. I have a few error codes coming up p1114, p1118, p1131, p1296 and p1140, so these are all to do with the o2 sensor from what I read, would this be the cause of my issues or is there a bigger problem there? any help would be appreciated.