The next step would be to see what PIDs are causing the problem. Tap the dashboard screen in an empty spot to start the data logging (You'll see a menu).
Save a log file. These have a .lgf extension.
Then you can email that to firstname.lastname@example.org
and we'll take a look. Please reference this thread in your email.
Alternatively you can also take a look here:http://www.palmerperformance.com/download/CALC_PID_Reference.pdf
Looking up the CALC.BOOST_PRESSURE shows you which PIDs go into the calculation of boost. So what we will do with the .lgf file is to look up those PIDs on the datalogging screen and see which PID looks wrong.