...a red truck with various parts removed.

I ruled out the following:

• ECU
• Fuel injector
• Fuel pump
• Radio
• Glove box
• Dust on the floor

What I have determined highly unlikely to be the problem due to it being replaced fairly recently:

• Ignition coil
• Ignition wires
• Distributor cap and rotor
• Throttle position sensor

What I have determined highly unlikely to be the problem due to it being not related to the symptoms:

• Water pump
• Radiator
• Clutch
• Brakes
• Headlights
• Turn signals
• Tires
• Starter
• Bodywork

What is confusing me:

• The ECU cleared the codes when it died the other night
• The fuel injector is spraying fuel even though there isn't really a spark (Note: A friend told me that the fuel injector will not allow fuel to pass if a spark isn't sensed)
• There is a weird rattling sound towards the back-passenger's side of the engine
• Sometimes it appears as though there isn't much compression