When I started up my car the other day, it turned over and cut off and made a popping sound from the exhaust. The CEL came on, and i went to autozone and they said it was a bad Cam Position Sensor, so i changed it and reset the computer by unplugging the battery and the light turned off. Now, it still does the popping thing from time to time, and i went to sears to check my battery and they said that it's fine but the alternator could be bad, but it doesn't sound like an alternator problem to me? Anyone got any ideas?