Smile [Q] Xperia L ROOTING Effects on warranty ??

Hi
I hav a sony Xperia L and i want to install a custom rom in to my phone . i just want to know if i root and unlock my bootloader and i install the customized rom in to my phone , will it effect the warranty of my phone bcoz it is just 2 months old phone and after doing all this if i do the repair through pc companion will it bring my phone to the same condition as it was before customizing ...I mean if i install the stock ROM again by pc companion will it relock the bootloader will i get the warranty back again ???????

Raunak kapoor