Are you using bluetooth? if so is it powered from the aux 5v?
I say this because today we experienced a significant 5v fluctuation causing both TPS and MAP to flutter. We know it was the bluetooth as we went back to wired serial and the fluctuation stopped.
The VEMS bluetooth adapter seems to be introducing noise onto the 5v.................... We are going to try and external 5v supply an see if that fixes it, but the wiring then becomes unnecessarily messy.