The Engine ECU in your X learns . It bases its fuelling on the inputs from the MAF, crank,cam, knock, etc sensors and then the resultant output from the O2 sensors. Over time it learns the best setting for ignition and fuelling to give the correct fuel air mix. When you change a sensor that can give a variable reading like the MAF, this "learnt" behavior can be upset if the readings it has got used to are a lot different from expected.

If this is this the case the ECU will quickly adjust the short term fuel trims to bring harmony back and smooth running whilst making a note of the adjustment and tweaking the long term trims. It can take a while for the ECU to settle down after replacemnt of these items so a reset of the adaptions or "learning" is called for. This just resets the ECU to factory and wipes its learnt fuelling adaption.

Your biggest problem will be that you have bought more than likely a Chinese MAF and it will no doubt not be too long before you get a MIL lamp and a code saying " out of range" or simalar as the MAF fails.
Just dont scrimp on these items.You may be lucky, but in my experience, you have just wasted your $$$$$$.