Your car’s mass air flow sensor measures the volume of air entering your engine so your engine control unit (ECU) can balance and deliver the correct fuel mass to the engine. A faulty mass air flow sensor will mean substandard engine performance, which can manifest itself in poor fuel economy, engine drag or hesitation while idling, engine hesitation and jerking during acceleration, or engine hiccups. If cleaning your mass air flow sensor doesn’t fix the problem, replace it with an inexpensive option from euromotiv.