Problem Running Rich

[turbospyder19]

My GST runs very rich. Everytime I get out of the car I wipe black crap off the bumper and my friends say it smells like gas when I'm driving in front of them. Could this be the cause of a bad O2 Sensor? Also, will this problem get worse when I get my new downpipe with test pipe? It doesn't seem like I need an SAFC yet, being as I don't hear about other nearly stock cars having this problem. I have my FPS bypassed because it went bad...bypassed or not, if its bad won't it still throw a code? My friend told me that when the ECU sees a code, it makes the engine run rich as a safety measure. Should I replace my FPS? Sorry about the list of questions, but I need to pass my second chance at emissions

 

[1993eclipseGS]

plugs, timing, clogged air filter, air/fuel mixture, wires, coil, etc.

 

[turbospyder19]

I've got new plugs and wires, new air filter...how do I check the coils? Pretty sure my timing is right, belt was recently replaced. A/F ratio...wouldn't that involve the O2 Sensor? How do you check those?