This fault code, as almost any other fault is more likely to involve wiring issues than a defective sensor. Just replacing the sensor without checking and repairing issues like bad connections, high resistances, or intermittent loss of contact in the sensor's control system is like taking candy for a migraine headache.
You need to take the car back to the mechanic who replaced the sensor, and demand that he perform continuity, resistance, reference voltage (if applicable), and ground connectivity checks on all the wiring that is associated with the crank position sensor. You will likely find that the issue was not a defective sensor, but a problem in the wiring.
Or, as Gaurav suggested, take the car to Barry, who is a competent, professional mechanic who will find, and fix the REAL problem.