94 saturn sohc 1.9 replaced map sensor spark plugs cleaned egr replaced vaccume hoses and the car runs terrible rough idle smells like gas and no power on exceleration

Start by replacing the air filter and checking the operation of the fuel pressure regulator. Have the stored codes read out of your ECU, either by an auto parts store or a local mechanic, in order to ascertain a starting point for diagnosis.

if the car is loud/noisy there is a hole in the exhaust system and this will cause a rough idle because of a loss of back pressure and the vales will not open and close properly resulting in the rough idle it also will make the engine run hotter and this will cause your spark plug gaps to increase and the spark will be less than needed to ignite the fuel in the cylinder for proper combustion which will result in poor gas mileage and lack of power is the check engine light on?

When checking for Vacuum leaks, did you use a water spray bottle on seams and vacuum lines and EGR pod?(engine running)

Check for air leaks in exhaust before O2 sensors. O2 thinks its running lean from air leak in exhaust header and enrichens fuel charge.

Fuel injectors dirty, not closing tight. Switch injectors to other bank and see if Error Code moves to relocated injectors.

Bad spark plugs, check if you have fuel runners in your intake.

So many options...oxygen sensor, egr valve, pcv valve, premium gas.

I know you mentioned the EGR valve has been replaced, but you may have a bad 'new' part. I know the car is electronic, but has anyone checked its ignition timing (timing belt been looked at, I know it only has 77k on it). Is the fuel pressure regulator OK and it vacumm supply?

Before we both knock ourselves out with fuel injector testing. Hook up a Digital voltmeter (DVM) to upstream O2 sensor and lets see how she is burning. Remember positive lead of DVM to signal wire and negative lead to ground. Anything above 550 mV is rich anything below 350mV is lean. Be mindful that an exhaust leak the size of a pin hole in this region can cause a rough idle. A healthy reading should bounce between 550mV and 350 mV.
Next to test is O2 is working block off air in take making mixture rich and see what O2 says about it . Then pull off a vacuum hose (a lean condition) and see if DVM drops to 200to 300mV's.
Keep me posted.

You have a fuel injected car. Things that can cause too rich would be a bad altitude sensor like the map or mass air flow depending on which one you have.
Anything that would cause excess air to go into the exhaust system like a cracked exhaust pipe before the 02 sensor, or low compression, or a stuck open pcv valve, intake gaskets, throttle body base gasket.
Or a Throttle position sensor which is telling the computer you foot is on the gas when it is not.
Its possible you have a bad PCM,, or coolant temp sensor saying the motor is still cold as its warming up.
Its possible you have a vacuum hose somewhere on the engine with a big crack in it or its just inplugged and you dont see it.

But my first guess would be possibly a bad computer.
Try creating a big vacuum leak when its loading up. It should run better.

Also if you have an egr valve it could be stuck open a little causing excess air or an idle air control valve stuck open.

Does it clean up if you rev it up or does it blow black smoke reved and at idle. This could point towards the altitude sensor.

By a ford

To check EGR valve, plug the vacuum hose to it, and it should not get hot anymore. It if does, it is leaking.
But gas smell is usually bad plug wire or plug.
With good insulation, remove one sparkplug wire at a time, to see if one has no effect. That is the target.

You replace alot of things but you should replace the EGR valve and the throttle positioning valve also. I would start with the EGR valve