2 sparkplugs blown (#4 twice) for a $1200.00 bill and 4 coils replaced. I'm starting to get the hesitation on acceleration when it is cold and around 1500rpm it hesitates. When the thing is warmed up it is not near as bad but still happens especially when starting off from red lights and so on. NO codes yet. With my 4 other COPs I got cel and codes. Anybody got an idea? Can the COPS and or plugs ( Motorcraft replaced 20K ago ) misfire without generating a CEL?