Runs ruff stalls when I stop to fast or make right turns. I have 2 codes that are both 300 multi miss fires. I have done a tuneup replaced the mass air flow senser and the egr sencser . Stills runs ruff has a smell to it right befor it stalls out. But the bust thing it acts up for two days then it will run right for one day no check engine light nothing I am lost and can not keep paying for diagnostics.Any help