Any Ideas...?

I been getting a check engine code on the tuck ever since the turbo install its a P2761 code, http://engine-codes.com/p2761_chevrolet.html

neways it happens when i turn on the truck, ill wait a few then i clear it with my plx and it seems to go away. Now the tranny was in the truck before and wasnt doing this. Ive read into some of the issues, being a faulty 2-3 solenoid
a bad ignition switch. dirty connections, a few other things basically that the switch isnt getting proper electric power to it. ive cleaned the connections, and bought a new switch " havent changed it yet". but i was wondering the only other thing is when i installed the new fuel pressure guage i tapped it into the ignition wire and it comes on now with the dash and what not. would it be enough to pull juice to throw a fault?