My Toyota Sienna (107,000 miles)has been a great car until last October when I accidentally ran over a portion of a boulder on the Blue Ridge Parkway. On the way home, the check engine light came on…obvious damage. After the insurance company replaced everything from my exhaust system, oil pan, gas tank, three oxygen sensors, etc. the light still comes on. What happens is within the first few minutes of starting the car, it’s like there is no power…like car in neutral or creeping along. I’m pushing the gas reving the engine up to 3000 rpm’s and then it kicks in. Maybe it will run beautifully for days; then light goes off. Computer reads “air flow sensor” code. It’s been replaced twice…same thing continues to happen. The mechanic took the car to have the transmission checked…everything a.o.k. During the seven days they kept my car, they didn’t have the problem. It happened on my way home after picking up the car and stopping for gas…light is currently on again; but will probably be off by tomorrow. It never happens when the car has been running…only upon initial start up and pull out. Plugs and wires replaced, fuel filter, air filter etc. ANY IDEAS???