performance on a budget ?? :)

i have a 99 Gt i have a drop in k&n filter, with one of the those chips that go in the IAT sensor , an some after markert muffler boxes. People tell once i install the ecu in it !!! It will make a difference wit 2.5 pipes . Wut do u all recommend i buy to my car ? They told that chip in the IAT sensor doesnt do any difference to my car !!

the "chip is a simple resistor you can buy at radioshack for like .20...they do nothing.and for your car i would go with a cai and get rid of the drop in filter.