Mitsubishi Repair: Turbo bogging down, mitsubishi eclipse gs, replacing a head gasket

Question
I have a 95 Mitsubishi eclipse gs-t manual transmission.  Recently I changed the head gasket.  It ran fine for a few weeks but now hesitates when I try to accelerate, when the turbo gets about half way...  The engine light is on and the codes are p0170 fuel trim malfunction and p01400 manual diff pres sensor.  Please help.

Answer
Rich,
These codes usually refer to a problem with the air/fuel mixture.  The mixture is either too lean (not enough fuel) or too rich (too much fuel).  Check to make sure the fuel pressure is accurate and that there are no restrictions in the intake.  For your car, you'll need to check everything from the air filter (MAP sensor), turbo, intercooler, BOV, throttle body, and even the EGR valve.  Since replacing a head gasket involves disconnecting several components, there's a chance a connection has become loose or damaged.  Inspect those areas and hopefully you'll find the problem.
Good luck!