Try going to a regular smog place and get a diagnostic done. I am going to have this done on my 96 Ls. I have a stock b18b1 engine, but failed smog and now car is considered a gross poluter, but got the smog at a test only place and they dont give repair information. So going to get a diagnostic test done to determine the issue so it can be fixed. most places wont look to see if the engine matches the car, so as long as you fix what is causing it to fail smog, then you should have no problem. I have a buddy that did a H22 swap in his civic hatch and passed smog with no problem, because the place didnt check to see it wasnt a civic engine, just saw honda and did the test. . . The B20 should not be that different from the B18, it is pretty much the same motor, even the JDM places state the B20 is for the CRV or Integra, so look wise, if you have the big intake manifold, they should be identical. . .