Slow down there chippy and lets look at what appear to be happening.
Lets start with the P0339
(PCM) detected an intermittent or erratic voltage signal from the secondary crankshaft position (CKP) sensor.
Potential causes for this code to set are:
Faulty or damaged crankshaft position sensor (most common)
Faulty or damaged trigger wheel (harmonic balancer, flywheel, an internal wheel on the crankshaft)
Wiring issue between the crankshaft sensor and engine control unit, shorted or open circuit
Defective CKP sensor Open or shorted wiring to the CKP sensor
Corroded or fluid soaked connector at the CKP sensor
Faulty PCM or PCM programming error
Besides just reading the code and swapping the sensor, have you completely checked and eliminated all other possible causes?
As to:” I replaced the starter with a NAPA starter about 6 months ago. Now with the starter issue, could the the starter be bad, and is what’s causing the sensor to appear bad. Could the starter not be supplying the right voltage to the sensor? ”
If you have a faulty starter, the two most likely issues would be a slow or no crank situation or s possible battery drain situation.
The starter does not supply voltage to the crank sensor.