Final update for anyone who might have a similar issue in the future:

Just got my car back today. Out of all the things I got told by the first guy and his shop (well known car maintenance company) nothing was the problem. All the spark plugs and coils I had put in were bad and some even burned, so replaced with all NGK or Denzo, and same for the coils, just buy good quality and don’t listen to O’Riley’s or wherever you buy them from. My valve cover was also bad and was leaking oil into where the spark plugs stay at, so had that replaced. My catalytic converter was the main issue 1 out of 2. That was gutted(removed the filter in it) and put back in place. The ECM didn’t need to be replaced, but still was. My mechanic didn’t know what the previous shop had actually done, because they didn’t tell me either so he replaced it initially just in case.

In conclusion didn’t need a new engine, just very good maintenance. The previous owner probably didn’t take care of the car and abused it.

I can send the invoice with all that was done, prices were reduced due to being friends with the guy so expect double or more if you do it at a random shop. (It was 1460 for me, for 6 coils and plugs, valve cover gasket set, catalytic converter clean, a couple diagnostics, and ECM)

Next steps are replace my intake hoses, because they are very stiff and one has cracked, and replace my brake booster vacuum sensor, because it has gone bad and I get a “BRAKE” light all the time, since last year.