[Working Principle] The outside air in the throttle will flow through the sensor, in the engine will remove a very large part of the heat, the more outside air flow, will remove more heat in order to maintain the necessary temperature of the air flow sensor, it needs extra current to heat the sensor, it will regulate the size of the air flow through the current. [Replace in time] When your car is idling, acceleration is weak, fuel consumption increases, black smoke from the exhaust pipe, etc. indicates that your mass air flow sensor needs to be replaced. Replacing the sensor will improve fuel efficiency, help the catalytic converter better remove harmful gases from the vehicle's exhaust system, reduce emissions, and prevent premature catalytic converter damage. [NOTE] Please clean the air box and replace the air filter before installing the mass air flow sensor, otherwise the code and check engine light may continue to appear even if you replace a new one. Mass air flow sensor