Hi i got a 2002 impreza wrx wagon. It has 120,000 miles but just replaced spark plugs, fuel filter,cleaned filter, and mass air flow sensor.the car has a really rough idle and fluctuates. I'm getting codes for misfires in cylinders 1,2,3,and 4. And a bank 1 too lean code. Idk where to go from here and what to try next. Any ideas would be appreciated.