[Johnny Mullet]

Now that you found it, whatever dirt is left in the hose would be minimal compared to the amount of dirt you already sucked through the engine. Good thing you changed the oil and got the air filter taken care of now! Just clean it the best you can and run it. The air filter will pick up the rest if any comes loose, just check it more often.

If the plastic piece somehow made it into the combustion chamber, it would have melted and been shot out the exhaust causing no damage. If it did not make it to the combustion chamber, it could be lodged somewhere in the intake manifold or stuck in an intake port. Worst case scenario is that it could cause a valve to stick, but the heat from combustion would melt the plastic anyway.

I would not worry about it if it were mine.