Dirty fuel injectors or vacuum leaks can cause a car to hesitate when the gas is pressed. It can also be caused by low fuel pressure.
The problem can sometimes be diagnosed using a scan tool. The tool checks for engine misfires and fuel readings.
If the owner suspects a vacuum leak, they should check to ensure all hoses are connected tightly and are free of holes and cracks.
The repairs the will be required depend on the issue at hand. For instance, it a vacuum leak is occurring, a hose may need replaced. If there is a lack of fuel pressure, the injectors or fuel filter may need cleaned or replaced.