2001 Infiniti G20 P0105 code issues

[alexbhpd9]

hey guys,i am new to site just did a bunch of searches but can't find anything specific for my problem. anyways i have a 2001 G20 that was given to me with a blown motor. i bought a used motor on ebay and installed the motor. everything is great car runs great but i am getting a steady check engine light and when i hook it up to a scanner it tells me P0105 barometric pressure sensor. i also had to purchase a new computer for the car. not sure what that code means or how to fix it. can anyone help. thanks in advance, alex i hope i put all the necessary info you need to diagnose if not reply or email me [email protected] thanks