1999 Chevy Tracker camshaft position sensor

Hi there,
A diagnostic showed trouble with camshaft position sensor. I replaced the sensor but the car won't start. It tries, and when depressing the gas I hear a "popping" sound like engine trying to start. Can you tell me what might be wrong and how I may be able to fix it? Is the position of the sensor important and could that be why it isn't starting?
Thanks!