When I start my cold engine during warm, humid weather, the engine idles erratically. The rev counter bobs up-and-down , varying about 200 RPM and does not stop until I put the CVT into reverse or drive. Then it's fine after that. It does not do this in warm, humid temperatures when the engine is warmed up upon start up. Only a cold engine. Anyone else experiencing this? Know the cause? I would chalk it up to a faulty mass airflow sensor perhaps, but I am no mechanic. It does this very sporadically, so I have not been able to show it to my Mitsubishi dealership.