Getting Code 31c and 31o..What to check.

CODE: 31 (KOEO) - EVP circuit below minimum voltage. Vref (5 volt reference voltage supplied by the computer) missing or broken wire or bad contact in circuit. Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or MAP sensor located on the firewall near the center of the car. With the sensor removed from the EGR and still connected, press the plunger and watch the voltage change on the brown/lt green wire. Check for the same results on pin 27 on the computer.