If you´re interested in doing your own power chips, check out this site...
http://www.sr20tuning.com/theoryandpartsrequired.htmlsame applies to most nissan ECUs including KA24E and manual CA20E. If u´ve got an auto CA20e, u need to reflash the micro as well as adding the eeprom and a few other additional components.
What u need to make ur own power chips:
EEPROM Chip (27C256) - $9 from jaycar (optional - u can always recycle ur old eeprom chip) OR use an old motherboard bios chips. most of these are 27C512 or 27C256 and are easy to come by.
EEPROM Socket - $0.20c from jaycar
EEPROM Programmer - $90 from ebay
Software - free
Dicking around time - free
a mate who can solder ur socket in for u - a few beers
If u want to get serious, u´d want some dyno time and a wideband o2 sensor.
Is pretty rewarding to DIY - there´s nothing to it if you use the software listed in the article.