I have had the same codes come up twice now, about a month apart. Both times I was travelling up hill @ about 1/4 throttle. There was a short loss of power and rough running the first time but only the loss of power this time. The MIL comes on of cource but the engine seems to run fine (full power etc.) within seconds of this happening. The codes that are set are:
P0234- Turbo overboost and
P2121- Throttle pedal position sensor, switch D circuit, Range/performancene
Both codes are set at the same time.
Can anyone direct me to the most likely cause?

Thanks