My car has started idleing really rough and to me sounds like its missing cylinders. It has a new fuel pressure regulater and the codes it gave me are a lean mixture and misfire on cylinder 2. The people i have asked have said anyhting from burnt valve to vacumm leak or egr valve. It started this all at once. My fuel economy has dropped off a cliff 20 miles on 3/8 of a tank. it has a blue tint to the exhaust and it smells like raw gas. After I ran the koeo test the car would not start i had to hold the throttle to the floor for it to start. Thanks in advance.