BRAVIA Engine 2 after rooting I have a Sony Xperia SP running jelly bean 4.1. I wish to root my device using the Doomlord exploit and run kitkat 4.4. But will that affect the working of the Bravia Engine 2 in my device in any way?
The bravia engine would need to be included in the new ROM you are installing. It is a software screen enhancement. 

http://allenramos.blogspot.ie/2013/05/enhance-your-android-phones-display-w.html?m=1


  The Sony Mobile BRAVIA Engine 3 is a video enhancement program for Sony phones. It uses filters and algorithms to create a clearer and more contrasted picture and an overall smoother experience.


Alternatively there are often flashable zip file mods for the bravia engine for different devices.