Posting the actual code (format: P1234) would be particularly helpful. There are lots of codes having to do w/ these. None of them point at parts - they point at signal anomalies in circuits. So don't assume that you need either one of these sensors.
Just as a starter guess though, perhaps it was something in the range of P0016-P0019 - which refers to the cam/crank signal correlation? This could very well indicate that the timing belt installation didn't go that well. How is the car running?