after changing plugs, wires, o2 sensor, mass air flow sensor the car seemed to run much better but still had lean codes. I was busy doing other things and when i got to drive the car again it was back to misfiring along with the lean codes. This time I noticed that the coolant level was slightly low ( about 1 liter) so I guess the intake gaskets may be the problem. I bought my wife another car so that I can take the ssei down and fix it an my own schedule. I wish the smoke test would have shown a vacuum leak from the get go.