1999 Dodge Intrepid Oil Light and Misfire
Well, 1684 just means the battery has been disconnected within the last 50 starts. 1391 means Intermittent loss of CMP or CKT.
Now, back to the engine noise. If your oil low pressure light came on when you came to a stop, then this means your oil pressure is way too low. The first thing you should have done when your oil pressure light came on, was turn the engine off and find out why. Is the engine low on oil? Is the oil pump going bad? Sometimes if you dont change your oil for like 10k miles, it will get bad and not be able to hold pressure at idle.
If your car oil pressure was bad, then you may have damaged the internal workings of the car. Cars make weird noises when bearing go bad, or when it throws a rod, or burns rings up. I would suggest taking the car to a shop and see if they can determine the extent of the damage.
If by some strange chance no damage has been done, then fix the oil pressure issue and make sure the vital parts of the engine are taken care of.
Suggested Repair
Stop driving if the oil-pressure light is on and check the oil level, oil condition, and oil pressure, including the oil pump. Have a shop inspect for possible internal damage from low oil pressure. Code 1684 only indicates a recent battery disconnect; code 1391 indicates intermittent cam or crank sensor signal loss, so also inspect the CMP/CKP sensors and related circuits.
Conversation Summary
The owner of a 1999 Dodge Intrepid 2.7 reported a flashing oil light at stops, followed by a check-engine light, jerking or missing, and a strange engine noise. Codes were 1684 and 1391, and the owner asked whether a rod or rod bearings had failed. One reply noted that crankshaft position sensors can cause problems on these cars. Another explained that 1684 means the battery was disconnected recently and 1391 indicates intermittent loss of the cam or crank signal. Low oil pressure may result from low or deteriorated oil or a failing oil pump and can damage bearings or other internals, so the car should be inspected before the oil-pressure problem is repaired.
