Agreed with gihan however would like to add one point, after disconnecting your battery its better if you can press your break pedal couple of time ( so that if the sytem has any power left it will be gone once the break lights work this i saw in the net and dunno how far its true )
once you start your engine do not throttle a loot and let it run idel for some time and then for couple of KM drive at a modarate ( during this time your ECU will remap automatically)
all the best