Without Speed Density Update

Mass Air Flow (MAF) / Manifold Air Temperature (MAT) Sensor:

The Mass Air Flow (MAF) sensor produces a frequency output which is directly proportional to the air entering the engine. The output will vary from approximately 32 Hertz at idle to 150 Hertz during wide open throttle. If the sensor fails at a low frequency, a code 34 will be set and stored. A code 44 or 45 may also be caused by a faulty MAF sensor.