Measuring boost back pressure

So calibration and scaling did change between firmware 1.5 and 1.6 on the MS but I think I'm just dealing with a faulty sensor. I use the same sensor for oil pressure and fuel pressure and they are all calibrated the same. I did update them to the new 1.6 settings and oil and fuel give the same outputs. I took the Valiant for another spin after recalibrating and get positive boost back pressure (1.5 back pressure at 5.5psi) but then the back pressure readings get stuck at 0.3 out of boost.
**Firmware 1.6: Select the “Linear 0.5v-4.5v” Option for an output range of 0.5V to 4.5V, corresponding to a pressure range values of 0 to 100 PSI.
**Firmware 1.5 or Older: Select the “Linear” Option for an output range of 0.0v to 5.0V, corresponding to a pressure range values of -12.5 PSI to 112.5 PSI.
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