Automotive Mass Air Flow Sensor MB1974003021 197400-3090 197400-3021 OEM Specification

Mass air flow sensor MB40003021 directly replaces OEM numbers 197400-3090 and 197400-3021, installed between intake manifold and air filter, accurately measures incoming air mass and transmits signals to the ECU to adjust fuel injection and ignition timing, directly affecting combustion efficiency and power output; compatible with most Mercedes-Benz and some General Motors models. Installation difficulty medium; about 30–45 minutes; clean intake paths and avoid touching sensing element. If there is rough idle, hesitation on acceleration, or abnormal fuel consumption, replacing this sensor can restore power.