2003 cavalier miss at idle rpm 500 to a 1000
2003 cavalier has a miss at idle rpm goes from 500 to 1000 i relaced plugs,wires,o2senser,iacsenser,control module,intake gasket,doesent have a pcv valve but unpluged a hole in intake cause it build pressure in valve cover and put oil in intake motor smooths out higher rpm has 60 lbs fuel pressure but only has 10 lbs vacum new air filter why is this car still missing has a p0300 code