The air flow meter measures the intake air flow rate by measuring a part of the entire flow. Measurements are made in such a way that the ECU receives electrical output signals varied by the amount of heat emitting from the hot film placed in the stream of the intake air. When intake air flows into the intake manifold through a route around the hot film, the heat generated from the hot film is taken away by the air. The amount of heat reduction depends on the air flow. The temperature of the hot film is automatically controlled to a certain number of degrees. Therefore, it is necessary to supply the hot film with more electric current in order to maintain the temperature of the hot film. The ECU detects the air flow by means of this current change. If the MAFS is bad, there will be an evident idle difference. These are Authentic Z32 N62 MAFS off 90-96 300ZX Models, all MAFS are tested on live vehicles before they are shipped out. We only offer initial install and start up warranty on these.