I have a 1996 Chevy Lumina Minivan. It died while driving on the Interstate, and would not restart. Towed it home and scanned it. Had a 300 code (Random/Multiple misfire). Upon inspecting, I found that the Fuel Pressure Regulator was bad (shooting fuel into the vacum line). I replaced it then changed the oil (because it smelled like gas) and filter. I got it to start, but really rough. Cleared the codes and restarted it for about a minute. The check engine light came back on, but it was flashing. Rescanned, and it is coming up with 2 codes, both say 305 (cylinder 5 misfire). Any Thoughts would be appreciated.
Since you were running so rich due to the regulator, you may have fouled a plug in cylinder 5. Remove it and inspect it. I would recommend replacing them all at this point, but that is your call. However, I would replace #5 to be sure it is good.