Since there was a lot of recent work, recommend CONFIRMING the motor grounding strap from the left hand motor mount to the left hand frame rail.
Have you checked all of the fuses in the engine bay and driver's kick panel? Especially I/P fuse #18.
Confirm there is key on +12 volts at the ignition coil RD/LG wire. Use a known good ground to test. Another easy location to test for ignition power is at the radio interference capacitors. If no power STOP and find out why.
Since there was recent work done, perform a through visual inspection of the wiring harness looking for any physical damage. Touching any hot metal parts for example. Pay special attention to the wire leading from the CKP sensor. Inspect the connector to the CKP sensor for bent/pushed pins or other signs of damage.
The P0320 DTC indicates the problem could be caused by the secondary ignition arcing out. This means that a through check of the spark plug wires should be done. Confirm that:
- all factory plug wire routing has been followed.
- all factory stand offs and looms have been used.
- that the spark plug wires are not touching any metal parts.
- confirm that the spark plug wires are fully seated on each spark plug.
- inspect the spark plug wires for white spots which is evidence of arcing.
EDIT: also seems possible to me that this "could" be caused by a crushed spark plug electrode touching the tip. The kind of thing that could happen from over RPM'ing and having the piston contact the plug. Consider that a hard grounded spark plug could blow the ignition fuse. The blown ignition fuse then causes the DTC.