0344 Code-Sensor Changed and now back

[Cajunsim]

I changed sensor about 1 month ago and all has been fine. Doing 70 on interstate and light comes on (limp mode kicks in) and is same code. Questions-1. Could it just be a bad part and new one should fix or do I have other issues. 2. What does the position sensor do (function) and what should I worry about when it indicates a code? Thanks.

[CREWZIN]

If it was OK for a whole month, I'd guess it's a faulty part. You asked about a "position" sensor but there has to me more in the name to tell you anything, like the "CAMshaft postion sensor, or CRANKshaft position sensor.