Totally fingers crossed here, but hopefully the problem with my car has been found.
After getting the used EGR valve and getting no change whatsoever, it came right down to my dad and I troubleshooting ourselves. My dad and I both did our own research and came down to these possibilities:
- faulty Idle Air Control (IAC) sensor
- faulty Crankshaft Position sensor
- faulty camshaft sensor
- faulty Mass Airflow (MAF) sensor
- faulty Throttle Body sensor
- malfunctioning ignition coil
- malfunctioning fuel pump
- disconnected/ruptured vacuum hose(s)
This afternoon, we went out to investigate the quality of everything under the hood. Other than a few exposed wires however, all we found was a damaged vacuum hose that connected to a fuel line. My dad picked up some new hose and a universal tee hose connector to fix the issue. It still had problems though, so we tested all the sensors by disconnecting them one by one restarting the car each time to see if there was any change. When we got to the MAF sensor, my dad disconnected it and I started the car. Lo and behold, it idled almost perfectly. He plugged it back in and the car died about three seconds later. MAF sensors cost around $100 brand new from most big retail stores (Advanced, AutoZone, etc). I was going to get a used one from a junkyard for $27 when my dad randomly stumbled across one brand new on Amazon for $33. I have it ordered and shipping now, so here's hoping that it makes my car driveable again.