Hi,
Sorry to hear about the problem. I spent many a year ripping out stereos, and remember this one.
E02 shows up for one of three reasons:
1. The battery for the car was unplugged for too long(usually more than an hour) or dead and the stereo has lost it's settings, it may need to be re-enabled by entering the five digit code in your manual. Frankly if you don't have the manual it will be cheaper to replace than "fix" and given there 100000 potential codes the prospect of manually attempting them all is all but pointless. This "feature" was meant as a theft deterent.
2. Your trunk mounted CD player has died and the stereo is just letting you know it's dead and needs replacing.
3. The wiring harness from the dash to the trunk is damaged and needs replacing.
Easy enough to tell, if the rest of your stereo works, the CD player is dead or wiring harness is damaged, if nothing on it works then it's locked out. In the first case tou can take it to a stereo shop to find out but the diagnostics alone might cost you $100. In all three cases it's usually cheaper to replace than repair and for about $200-$300 you can buy a far better aftermarket stereo with a lot of new options that the NSX factory one doesn't have.
Personally I would favour replacing the stereo, but if your handy with a voltmeter you could test the harness yourself. It's the only option that would be notably cheaper than replacement..
Feel free to comment back on this post if you have any further questions, I will add a link to the end of this post that shows in a little more detail what I am referring to:
Hope this helps FixYa,
Chris
http://www.willmanselectronics.com/changers_ah.htm