This sounds like a leaking fuel injector(s)! If you are finding gas in the oil pan, be careful how much you're running the engine because the fuel is likely washing down the cylinder walls. You can test your fuel pressure drop after the engine is shut off. The pressure should stay within 10psi after the engine is shut down. If the pressure is ok, this could be a temperature sensor making the computer think the engine is very cold, causing it to richen the mixture too much.