It's quite possible that the servo is going out. Check the wires and make sure there not rubbed in a spot and bare, check to make sure that the wires are plug into the reciever snuggly and not bouncing around in the hole. Flip flop the throttle servo for the steering servo (do it at the reciever with out taking the servos off the car) and see if the steering servo stops working in the throttle position on the reciever.