2003 Peugeot 307 car going into limp mode when temp indicator is showing 12 degrees or less

I have a Peugeot 307 Hdi 110 bhp 2003 which is causing me some issues. The car is going into limp mode in the mornings and limits the rev's to 3000rpm for about two or three miles. After this time the car kicks in and all is well for the rest of the day. I have had the car to the garage and they have put it on fault diagnostic which has been indication a problem with the Air Pressure Sensor. I have had three different air pressure sensors fit by the garage but still have the same problem and now seem to have give up on the problem.Is this issue something to do with the outside air temperature sensor maybe as the problem only occurs when the temperature gage is showing 12 degrees or less....Your frustratedly Bazabond..