Some conditions that can cause a PO 102 are:
Poor connections at the PCM or MAF Sensor
MAF sensor wiring harness damaged, or routed too close to spark plug wires
Plugged up air filter, air intake duct or objects blocking the MAF sensor inlet screen
Vacuum leaks at throttle body, intake manifold, EGR valve flange or pipes
PCV Valve faulty, missing or incorrectly installed