2000 Saturn SL1 flood damage

dryed out replaced starter started and ran well (idle seemed high) for about 20 miles car died suddenly replaced coil pack(salvage yard part) started and ran well for a few miles (idle high) then died again borrowed a obd2 reader from autozone 2codes egr and idle high talked to josh mech at our local saturn dealer he said its probably the coolant sensor?...........ooooooookkkkk
"i can just replace parts till iget it right and save the labor cost"
anyone please help

  wimp