After replacing the crankshaft sensor, there are a few things you should do to ensure that your vehicle runs smoothly. Here are the steps you can take:

1. Verify the installation: Make sure that the crankshaft sensor is installed correctly. If it is not installed correctly, it can cause your vehicle not to start or cause the check engine light to turn on.

2. Reset the ECU: Use an OBD scanner to reset the ECU so that it can relearn the position of the new sensor and clear any error codes. Alternatively, you can disconnect the battery for 15 to 20 minutes to allow the ECU to relearn its position and clear any error codes.

3. Test the sensor: To test the crankshaft position sensor, you can connect both leads of a voltmeter with the terminals of the CKP sensor and set your digital multimeter to the AC voltage setting.

4. Check for other issues: If your vehicle still wont start or runs rough after replacing the crankshaft sensor, there may be other issues that need to be addressed. For example, the wiring could have been damaged during installation, or the sensor itself could be faulty.