Rough Idle, horrific smell

(At the bottom of this note, I will provide what I have replaced on the vehicle)

About two weeks ago, my oil pressure sensor went bad and I spilled almost all the oil out of the vehicle. Got that fixed but still had the left over oil all on the engine and such. About four days later, my starter went out-I fixed that too. Now when I went out to start my van to "warm it up" and came back to it about five to seven minutes later, the engine was shut off but the heat was still on (cold though from not warming up all the way) and the radio was still on. When I started it back up-it ran extremely rough as if the spark plugs are trying to fire all at once and I noticed an awful smell coming from the air vents. It smelled like burning plastic/wires or as my wife describes a strong nail polish remover. It threw two codes, one of which was P0137-02 sensor circuit low voltage bank 1 sensor 2 and P0300-Random/multiple cylinder misfire. I just recently replaced the spark plug and spark plug wires. With the way it runs at start up-its not drivable at all. Any idea where I should begin or any idea what it is? I have talked to three mechanics whom unfortunately have not looked at the vehicle, but they all do not have a clue.

Here is what I have done to the vehicle within the last one to two years:

Serpentine belt.
Spark plugs and wires.
Starter.
Oil pressure sensor.
Oil change regularly.
Motor mounts.
Ignition control module.
Upper and lower intake gaskets.
Coil paks.
Thermostat.
Cv axle (front driver and passenger).
Wheel bearings.
Wheel hub assembly (driver and passenger).
New tires.
New window switches.
Washer fluid pump.


I have spent a great deal into this van! I hope you can help. Much appreciated!
-Adam