i have a 2006 f150 dreaded 5.4 3 valve. i have had a problem with it misfiring when it hits overdrive and idling. i started with a new coil in the cylinder that wouldnt change when i unhooked the coil. ending up being a bad plug in that cylinder. it was the second from back on passenger side. so i changed the plug and i have more power but it still misses in overdrive. i am ready to sell the truck if i cant get this fixed. ive checked coils injectors and changed fuel filter. im not sure how to clean the mass air flow sensor. can anyone help me please. i dont have money to put it in the shop.

 

How many miles on the rest of the plugs? If over 60k, change them all. If it still misses, change the rest of the coils.

 

the plugs only have about 30k on them. i found another cylinder not working properly so i pulled the plug on it and its firing yellow. does that mean the plug is bad? it has a brand new coil on it.

 

What brand plugs and coils are you using?

 

Dealing with missfires is a simple process IF you have access to a decent scan tool that reads mode 6 live missfire counts. Find some one who will scan your truck. If the plugs are an off brand put in ,otor craft. Modulars are picky about plugs.

 

motorcraft plugs is what im using but not sure what coils is on them. i dont have anyone i know with a scan tool and cant go pay 100 bucks to get it scanned. im gonna go check some more today

 

Parts stores will usually scan your vehicle for free, Autozone does, around here anyway.

 

I don't think parts store scanners read mode 6 data, they only read codes.