2005 Chevy Impala Speedometer & Steering

My speedometer sticks, it will accelerate, but it won't go back to zero. After the car warms up it will go back to zero in 5 mph increments by turning the ignition to the on position and then off again repeatedly. To fix this, is it a cable or a sensor.

Also, when driving the car you can feel a catch in the steering and this happens at all speeds. What could this be?