Originally Posted by DK Pony
I believe he is saying you have your systems confused.
IAC is the Idle Air Control.
MAF is Mass Air Flow
MAP is Manifold Absolute Pressure
The MAF and MAP are kinda similar but not really. One came before the other but they are very different.
I would think that if your vehicle didn't come with a certain sensor or system then the ECU is not going to have the necessary software and information to use it properly.
Changing the ECU alone wouldn't do it you would have to change the sensors to match the ECU as it does more with other systems the newer the vehicle..Sounds like a PITA to me.
What DK said. MAP and MAF are two very different systems, and not interchangable.
MAP is basically a barometer sensor placed in the intake stream. As the throttle blades open, the manifold vacuum decreases
and thus, the manifold pressure increases
. Combined with the Throttle Position Sensor, the PCM can use both inputs to derive exactly how much air is flowing into the motor, and set the injector duty cycle for a stoich based on that incoming air volume.
MAF is basically a heating element placed in the intake stream. The wire is heated to a specific temperature (I've heard numbers from 120F to 170F), then the temperature of the element is read during vehicle operation. As more air enters the motor, it will carry away heat from the wire, and the wire temperature goes down (meanwhile, IAT goes up). Combined with a Throttle Position Sensor, the PCM can calculate how much air is moving into the engine based on how much the wire has cooled and how far open the throttle blades are.
MAF is more popular on boosted setups because it can meter a very specific window of air volume flowing in, for a better tuned stoich- It also is very good for compensation going from sea level to a high altitude (denver) since it meters actual air volume. But the heating element can go out or the thermistor can read erratically, and the life span is thus shorter. MAP is more popular on N/A setups because it can manage the manifold vacuum compared to the ambient barometric pressure, and is much cheaper and more robust. But if you go from sea level to Denver, it will detect an air pressure change and change the stoich accordingly, but not near as accurately as the MAF.