[Piwoslaw]

My diesel has an air pressure sensor just after the turbo. I'm wondering what the effect of changing its signal could be. Would tricking the ECU into thinking the pressure is greater (more air) or smaller (less air) result in using slightly less fuel for the same amount of work? On the other hand, the ECU's map could already be fine-tuned to the lowest possible fuel consumption and fooling around with the signals would reduce fe, increase emissions, or both?

I'll add that my turbine is supposed to have variable geometry, so hacking the pressure sensor may put more or less air into the cylinder. Or maybe manually changing the turbo's geometry would be a better idea? Then the ECU could compensate for more/less air in the most efficient manner?