I have a 9-5 Aero Sedan, 2003. Car idle roughly, hesistate and jerks during accelaration as if it's losing power. Additionally, white smoke is being emitted from oil filler spout during startup but clears up in 1 minute or less. Upon inspection and scanning, received a code that indicated #4 spark plug was misfiring, I replaced the 4 spark plugs as well as replace pcv valve, coil pack, fuel filter and change the air filter. I believe it might be vacume leak. Any ideals as to my mechanical issues..