AAPTS Sensors / Position

The AAPTS is the sensor to the outside world for the engine.

It should be located in the same airflow that the air filter sees.

Normally this is within the engine cowling and in the vicinity of the Air filter.

It should not be projecting outside of the cowling or far removed from the air filter.

You want to be measuring what the engine(Air Filter) is seeing, not the wing.

However, if your induction system consists of a closed air scoop/duct system that channels ram air from the airstream directly to the air filter, then the AAPTS should be installed to measure the air within this duct. Technically it is Ram AIr but it is the ambient air the engine is operating in.

The ECU uses this Ambient Air Pressure(APP) and Temperature(AAT) information along with the Manifold Air Temperature(MAT) and Pressure(MAP) to control the fuel flow.

If the sensors are measuring values wildly different from what the engine is actually seeing, your fuel mixture will be affected.