"sold" is more accurate than "sells", since there's no more available! better to stick to blazt ones rather than DIY ebay jobs, unless you have
that circuit is calumsult one, calum on sr20forum made those DIY kits which were supposed to be "DIY", not to be whored on ebay by someone trying to make a buck off someone elses work.
http://www.sr20forum.com/rom-ecu-tuning-fi...tester-box.html
answer these:
what com port is ur usb/serial adaptor?
what brand is it?
what drivers are you using? where did you get them from?
are you using that com port in any programs you're trying out?
have u tried other consult software? (ecutalk, tecu, calumsult?)