i went to autozone and got my car scanned due to a check engine light. I threw 3 codes P0442, P0401, P0300. I searched for the vacuum leak and found a hose that was off. I was just wondering could the random misfire be due to using champion spark plugs as opposed to motorcraft? I was told this could be the cause of my poor gas mileage. And what should i do about the insufficient flow to the EGR? All info is appreciated.

 

might be the DPFE sensor where was the vacuum located that was lose

 

if you have a misifre find out what cylinder it is...change the coil pack on that one and get all new 8 sparkplugs from Motorcraft..well the motorcraft ones i mean.. i did that and it solved my issue, woke the car back up and got better gasmileage.