When a car is sputtering when stepping on the gas or upon accelerating it's usually because of the engine not getting enough fuel.
The issue could be caused by clogged fuel filter, clogged fuel injectors, low fuel pressure, clogged fuel lines, bad throttle body etc.
The issue with a car sputtering upon accelerating could also be an ignition and electrical issue such as bad spark plugs, bad spark plug wires, bad spark plug wires, bad ignition coils etc.
Another cause could be a bad oxygen sensor or bad map sensor.
When a cars map sensor goes bad the bad map sensor can cause the car to sputter, misfire, run rich, surge and even die out.
A map sensor is essential to a properly running engine because it monitors the vacuum on the engine and tells the computer how much fuel to send to your fuel injectors.
When the map sensor is bad it can cause the engine to get too much fuel which causes the engine to run rich, run rough, have black smoke out the exhaust etc.
The bad map sensor also can cause the engine RPM to fluctuate or surge, primarily at idle or low speeds.
The map sensor stands for Manifold Absolute Pressure sensor and it helps monitor the airflow and control fuel to air ration on the engine.