[boxster]

i have recently installed a chip from next level performance. they claim that it gives up to 20 hp gain, but to be honest i hardly noticed a difference in power. i contacted them and they said that the gains wont be noticed immediately, but after a few hundred miles.
a friend of mine suggested that the chip will work best with a remaped ecu, but nobody does ecu remapping where i live, so that will mean taking the ecu out, posting it with fedex then waiting for it to come back and installing it all on my own. im worried that if i do this an engine light might come on.
does anyone else have any experience with performance chips?
and also, will changing the injectors help perhaps?