The work I have done to enable the SCIAP sensor allows much smoother operation of the throttle, and prevents the engine from surging unexpectedly. HP Tuners has added the base configuration of the Linear and Offset to their database, and it can be requested on any specific vehicle. This is not the end of the story though, In order for the Barometer to function correctly, there is what im calling a smoothing factor that keeps the calculated barometer within the bounds. I have not given this value to HP tuners yet, but probably will if there is enough demand.
The SCIAP sensor is a standard 1 Bar MAP sensor that sits after the throttle blade but before the roots of the blower. This allows the ECM to know the air pressure before the throttle and after the throttle and helps determine if the throttle is functioning as expected. The cursed P0121 is fixed by the addition of this sensor.
Link to SCIAP enable and configuration Product
The SCIAP bracket pictured above I milled out of Aluminum. I am able to make more of these if there is demand. It mounts right on the side of the snout behind the Throttle body. With 1/8″ npt pipe, It is very sturdy and doesn’t need to be remote mounted.