We bought our new 2009 Corolla last February. I noticed that the engine tends to idle-hunt coupled with a "woh woh woh" sound during cold starts (lasting about 15 seconds) but thought nothing of it because I thought the engine was brand new and just breaking in. In the next 8 months, my wife and I took a couple of road trips: Arizona and San Francisco. We racked up about 9000 miles. However, the idle-hunting and strange sound during cold starts are still there, again lasting about 15 seconds.
Anybody else experiencing this? Would it cause engine problems in the long-run? Does anybody have a solution?