When car begins to mist what does it mean - 1992 Oldsmobile Cutlass Ciera

Assuming the engine settings are correct and the motor is in good order it seems you must have a massive carburettor problem.

When the intake valve closes, the moving column of air stops abruptly causing a shock wave to travel back through the intake and even back through the carb gathering more fuel. The more wild the camshaft the greater this effect.
The air box is necessary to contain the fuel mist that is ejected and hold it ready for the next induction. If no air box is fitted then ram pipes should be used, a size selected sufficient to hold the fuel mist.
An open carb will allow the mist to disperse leaving the next induction with a very lean mixture.

An engine dying with the airbox fitted indicates a very rich mixture.
I suggest you begin by checking the valve timing and other settings and do a cylinder leakage test to ensure the valve seats are good.

misting up can be no air ventilation getting in the car have you checked the pollen filter it can do this if its blocked.

Check where the mist is forming.
Does it smell like anti-freeze?

A lite mist on passenger side with loss of coolant you should do a coolant pressure test.

Code 316 is an extension of your Code 304. 316 means its misfiring in the first 1000 RPM's and 304 means number 4 cylinder is the problem cylinder.
Could be a bad wire, coil, or sparkplug.

Do you mean the oil drain hose that goes from the flame arrestor up by the intake manifold down to the oil mist eliminator on the driver side of the engine block?
That hose is a bit of a PITA to replace, especially if this is a California car with an EGR.
If I were doing it, I would go ahead and make a day of it, pulling off the intake manifold, removing the oil mist eliminator and cleaning it out, and cleaning out all the vacuum ports on the manifold, and cleaning out the EGR piping (if applicable). That way you end up with everything flowing as it should and a nice fresh intake manifold gasket. I suspect you will find that the car runs better when you are done.

if it smells sickly sweet and there is a fine mist you most likely are leaking coolant into the heaterbox. generally this means a leaking heater core.

This Code means lean fuel mix on Bank 1. There are several things which can cause this reading. They are a Dirty MAF sensor (which can be cleaned with Electrical Cleaner, no solvents like Choke spray), and Vacuum leaks.

You can spray a water mist with a spray bottle around the gaskets. When the engine is running the RPM will change when you hit the open spot. Then you either try tightening and retorquing the bolts or replace the bad gaskets.

If you happen to have the 3.8 motor they used a 2 piece intake and the gasket between the 2 pieces failed alot.

My information also points to the fuel delivery system as a cause of a Code 171, which could be low fuel pressure. You may just need a clean fuel filter.

It would seem that your a/c is working very well. You most likely live in an area that is high in humidity. When the cold air from your a/c hits the moisture saturated air from the environment it turns the moisture to fog "condensation" . That is most likely your mist. Hope this helps. Good luck.

Replace the thermostat in the engine coolant system - should be near the water pump or in the top hose to the rad. Mist in the heater vents usually means a corroded heater core, that should be replaced. Be sure to use the correct mix of anti-freeze, to keep the boiling point in the cooling system correct. Many who live in the warmer states, thing that plain water is OK, but it is NOT. Antifreeze contains corrosion inhibitors that protect the engine cooling system.