I just bought this car. 2003 wrx wagon. The car came with a td05h turbo and some issues. When I had purchased the car it was running a little ruff but not too bad. I hooked up my OBD and it said rear o2 sensor. I replaced that. Code will not go away and OBD is now showing misfire in cylinder 1, 2, and 3. The guy I bought the car from has since replaced the coil packs and spark plugs. No change except for sometimes there's misfires now in random cylinders. The car runs fine but has a little shake when idling. Since I bought the car I have installed a helix dp, cobb ap, HKS bov, my exhaust should arrive any day now in the mail. I do not run the car hard as I have seen smoke coming from tailpipes sometime when excelerating. I have added some sea foam to the fuel in hopes to clean up the fuel injectors. I have three questions.
Is the car ok to drive?
What is my next step in diagnosing the issue?
Would the car even be running if all three cylinders were misfiring?
I understand I need a tune but I need to figure out the misfire issue before I get it done.
I understand I bought a lemon but I'm stuck with it now so hopefully the problem is an easy fix.
Thank you in advance for any tips