09 silverado changed plugs ,coil paks ,wires,cleaned trhrottle body.Added three tank fulls of fuel injector cleaner.still saying misfire #6 cylininder. changed coil pak and plug and wire again on # 6. upon initial start up ,after driving a mile or so ,CHECK ENGINE LIGHT FLASHES AND STABILITRAK is on . I pull over shut off truck ,wait a minute restart most of the time it runs great all day . until the next morning
SO FRUSTRATED

 

I had the same problem for cylinder 5 on my 08. I had changed the plugs maybe 7 months ago. I tried to go cheap and ordered AC Delco plugs on ebay. Turns out they were cheap knock off. Had the plugs changed to real AC's. Problem fixed. I learned my lesson, you get what you pay for.

 

I would buy a Diablo sport Predator tuner and deactivate the cyl delete system. when my cyl delete died i had to update my engine 5.3 vin 0. As it would cut off the coil packs and cause a misfire. I really enjoy my non DOD 5.3 .