RC CAR NOT MOVING

RC CAR is not moving after programming whtat could be the problem .
i have gone overv the code again and again i did not see my mistake. i used arduino car chasis , 9v battery ,mp3 remote , ir receiver. am not in hold of my code i would have sent it.

Could it be the 9V battery?

Does the car move satisfactorily if you connect the battery directly to the motor leads ?

Are the car motors rated to use 9V ?

Please post your code and a link to the car chassis that you are using when you can

UKHeliBob:
Are the car motors rated to use 9V ?

Are the car motors rated to use 9V minus whatever the drop in the motor driver is?