P0320 = Ignition/Distributor Engine Speed Input Circuit Malfunction
First check the 20 amp ECU fuse in the under hood fuse box. Also check the O2 sensor fuses. If good, next check for battery voltage on the tan/black wires going to the coils while cranking. If good, check for ground of 0.05 volts on the black wires going to coils while cranking. If either is missing, check O2 wires for chafing or rub thru on heatshields or other objects under vehicle. Verify the O2 sensors operation is correct, if so - suspect the ignition failure sensor.