when i start my car up on a warm start sometimes the rpm will rev up and i give it a little gas to keep it from stalling then when i switch into gear it will sometimes stall or the rpms will shot up to 2 or so. Im thinking it either my pcv or egr but it anyone has any ideas i would really like the help. also this wasnt happening when my dad had it 2 years ago but when i got it i put my system in so could it possibly my alternator.

thanks you
anthony