I can maybe help you out here. I had a 1996 that I turbo'ed and pretty much deleted all the emission stuff, but still had to pass OBDII. Pretty much you unplug your EGR temp sensor (kind of a B to get to) and jump the connector with a resistor. I'm not sure what Ohm you need, but you should be able to search this online. Pretty much the ECU thinks it's at the appropriate temp that doesn't require EGR operation. The ECU never tries to operate the EGR system therefore never throwing a code. Look here (
http://www.nicoclub.com/FSM/240sx/1997/el.pdf) page EL-218 & EL-219 for the location of the plug. Hope this helps, good luck.
As I was typing this I found the old thread I think I used like 8 years ago lol.
resistor-for-egr-temp-sensor-t94395.html