If anyone has used this/know about this sensor,if I have a pressure difference of say 0.1 or 0.001 kPa,will it be able to detect it?
I have used many pressure sensors, in many different ways 
This sensor is a purely analogue device, so it will sense as low a pressure differential as you like - the practical limit is determined by your measurement circuitry.
The Arduino ADC has a resolution of 10-bits, which is 1024 steps over a 5V range. So one step is 5V/1024=4.88mV. The MPXV7002DP sensor has a sensitivity of 1V/kPa with a supply of 5V. So one 4.88mV step is 4.88Pa, or 0.0048kPa. So the Arduino will not be able to detect 0.001kPa change with this sensor.
To detect a change of 0.001kPa (1.0Pa), you'll need to be able to detect a change of 1mV. That will need at least 13-bit resolution over 5V ( 5V/(2^13) = 0.6mV). If you can live with 0.0012kPa resolution, then you can use a 12-bit ADC. Either use a different processor, such as my beloved XMEGA series, or a standard Arduino Uno with an external 12-bit ADC. The ADS7822P would fit the bill.
The sensor is ratiometric, which means it gives an output which is proportional to the supply voltage, not an absolute voltage. So be sure to use Vcc as your ADC reference, and not a precision voltage reference. That way, as your supply voltage varies, both the ADC reference and the analogue signal will vary together and the variation will cancel out in the ADC conversion. It appears to be a paradox, but in this case a 'precision' reference gives you a less precise result, because the reference will stay constant as the signal varies with supply voltage.