Default 2G not available...help

guys..I have been flashing different ROMs and kernels.. yesterday flashed a ROM and it got stuck after sometime..rebooted.. changed kernel.. imei lost...restored files from previous backup.. changed permissions.. now its working.. but only 3G...if I select 2G only mode, signal not available ...emergency only...why?
THANK ME IF I HELPED.....

Device : Samsung Galaxy s captivate kitkat with xposed framework

Device : LG OPTIMUS L3
Rom :CYANOGENMOD 9 ICS 4.0.4 with XPOSED FRAMEWORK and OVERCLOCK 1GHz with RAM EXPANDER