Acts like it out of gas but has gas

Change the fuel pump and filter. due to its age its time to replace them.

you need to read the manual for the machine you are hooking to the vehicle .
These are errors not codes you need to understand how it works better.

Could be clogged fuel injectors. I had a problem similar to this. Car ran okay on flat areas but would spit and sputter going up inclines. I took mine to an oil change place and they ran a cleaner through the system. This fixed the problem and I put an injector cleaner in with every 3rd tank of gas to keep this from happening again.

water in gas

check you have good earthing points, also check the earthing strap from engine to shell. main earthing point follow the negative lead it will go to the shell.

Check your fuel filter again. Dirt from the tank could have clogged it again.

Sounds like you have a bad bcm as far as the lights ! The running rough and the cel flashing indicates a misfire condition ! Check your plug wires and see if a critter hasnt chewed a wire !

Could be a clogged fuel filter, and or dirty fuel injectors. Try running some strong injector cleaner through it. It may take 2 or 3 times before it cleans the injectors out fully.

Did you re attach the vacumn line you disonnected to inject the seafoam? If so it sounds as if the seafoam has not fully cleared the lines.

Hello

I am also facing the same problem

http://consumerguideauto.howstuffworks.com/1990-to-1994-chevrolet-lumina.htm

This will help you

Thanks