I would hold off on that.
Remember what I said about 5 minutes of Googggggggggglin?
Pay particular attention to the section that says diagnostic aids. Bet your eyes open a little wider when you see the EGR mentioned.
GearChatter.com :: View topic - DTC P0121 TP Sensor Circuit Insufficient Activity
Off to look up the EGR code and find the connection.
Edit: nothing on gearchatter about P1406, once I hit an FSM or anyone else that can, look up P1406 and find where it says something about TP sensor. That'* the area we want to head for with this one.