Oil pressure could be OK. Dakota's are wired so that when the oil pressure drops the fuel pump is shut off to prevent engine damage. It might be a sensor problem. Unplug the wire connector going to the sensor and clean the connectors on the wire plug and the sensor itself. If it still has the problem after that try a new sensor.

Jimmy

 

for starters.... check your oil level

 

...
+1

 

If your oil level looks good, take a look at the oil pressure sensor connector. By design when the sensors leak on most DCX cars, it leaks into the connector and shorts out the sensor causing the gauge to drop. If the connector looks wet inside it when you disconnect it, replace the sensor.

 

Cause Repair

1. Low oil level. 1. Check and correct oil level.
2. Faulty oil pressure sending unit. 2. Replace sending unit.
3. Low oil pressure. 3. Check pump and bearing clearance.
4. Clogged oil filter. 4. Replace oil filter.
5. Worn oil pump. 5. Replace as necessary.
6. Thin or diluted oil. 6. Change oil and filter.
7. Excessive bearing clearance. 7. Replace as necessary.
8. Oil pump relief valve stuck. 8. Clean or replace relief valve.
9. Oil pump suction tube loose or damaged. 9. Replace as necessary.

if you're down there pulling that sensor, might as well put a pressure gauge on it and get a true reading that way

pressure for the 3.9/5.9 is 6 psi idle and between 30 to 80 psi at 3000 rpms and the 4.7's are 4 psi at idle and 25 to 110 psi at 300 rpms, this is what the factory manual says