Running rich, gas in the oil pan.
Wow, similar questions on the Rangers this weekend. Perhaps faulty injectors dumping too much fuel into engine. They can be stuck wide open or get clogged as well. Would have a look at the fuel pressure regulator too. If gas spurts out of the vac line on the FPR you have issues there. They also can be tested with a hand vacuum pump. Those are/were some nice trucks, I think many people were unhappy to see them discontinued. Good Luck!
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