performance result from wrong injectors

[cre]

Putting high impedence injectors in a system built for lean injectors with a resistor pack in place is only guaranteed to run lean and burn valves or melt a pitson. If you remove the resistor pack and install high impedance injectors then you're in the same place as before and it's a moot point. Excessive fuel isn't going to increase NOx... NOx is a post combustion heat problem and running super rich generally pulls down exhaust temps in a big way. I'd start with checking both the mechanical and ignition timing, make sure the cat isn't clogged from debris, inspect plug wires, test the injector resistor pack.

With an '88 you need to refer to the TSRM for '86.5, '87 and '88. There were a lot of changes to the electrical system starting toward the end of the '88 model year. You can find scanned versions at the link below (I think you need the EFI PDF):

http://www.turboninjas.com/mk3supra/


EDIT: I just saw the mention of the knock censor code... That'll screw ya. It causes the ECU to literally dump in a ton more fuel and reduce ignition timing heavily. It's an absolute way to fail emissions although the high NOx still seems off. Fix the code 52, if that triggers at any point when they're testing it your stats are going to soar and even if it only happens for a moment you've already failed.. They don't average your emissions results, you have to pass for the whole duration of the test.