i have a 07 w/ a 2.7 motor. last week my wife was driving and she said it would'nt pass 45mph. i took it to the dealer and it was fine when they drove it. now it did it again yesterday, and when i took it in it was fine again. they said they cant do anything b/c it's not having a problem when there test driving it. she said it does'nt rev out or anything it just does not go pass 45 and the gas pedal feels stiff and would go down all the way. i cant really give any other info b/c i did not drive the car when the problem was occuring. any ideas on what could cause this problem would be very helpful. thanks.