Originally Posted by M5 TT
Yes it does but with piggy back stuff it fools the ecu into thinking it is making low boost so te ecu ups it to where it thinks it should be so the ecu only ever sees standard boost.
If the tech looks at air flow it would show the extra boost in extra air flow. Once I get round to fitting my burger tuning module I will log boost before and after and post results. But guaranteed to be standard both times where as the air flow will jump considerably.
Depending on how many sensors are manipulated by the piggy back, there will be a number of inconsistencies when they check the ECU:
Boost and airflow don't match
Fuel pressure and fuel flow/output signal to fuel pump don't match
Pretty sure BMW HQ knows how to detect that a piggyback has been on the car, if they want to find out... (like in a warranty claim case)