2011 Dodge Avenger Crankshaft Pos Sensor

[crthmu]

Back in October the check engine light came on and the code was for the crankshaft position sensor. The car died a few days later and I replaced the sensor and it came right back to life. Since then I may have put on another 10,000 miles and the car died last week. On a hunch I went and bought another crankshaft position sensor and replaced it. Again, it came back to life. My concern is - Why has it gone bad so soon? Is something else wrong? I do not want to go someplace and get stranded. My plan is to by a spare sensor and keep with me....but I would like to find out if there is an underlying problem and fix it. Thanks
c