I recently had the gas tank fixed (had a hole) and now the check engine light has been on. IDK if they are related but Im trying to figure out where I should start to fix it. I dont even remember if it was on when I took it in for repairs. It had sat for like 7 months because it needed new rack and pinion (which the same guy also replaced) The car seems to run fine. The mechanic didnt even notice the light which makes me annoyed. I been reading different posts and cant solidly figure out if my car actually has a code that can be read?

Yes there is a black single pin connector under the drivers side kick panel.  You have to connect the pins and then turn the ignition switch on, but don't start the car.  Count the CEL light flashes.

Lots of videos out on youtube, here's one.

https://www.youtube.com/watch?v=3y55wdRsa3Q

Larry

yep, check https://www.troublecodes.net/subaru/

for a list of codes.

The ECU's in those cars are routinely bad due to solder joint cracking, etc. It may not even be a legitimate code that needs to be addressed. Those 90 to 94 ECU's were very primitive and don't have a lot of codes to display in the first place. The most recent 90 I owned had about 6 codes that would never clear - replaced the ECU with a LINK standalone and manifestly there was no issues at all with the wiring as the LINK runs perfectly and has no complaints about any of the sensors (still original). 

GD

I used my phone to video the flashing code. Then I could turn off the ignition and decode it without rushing.

Its very helpful to keep as a record for later.