I have an 03 Expediton with 4.6L
It has developed a misfire and the check engine code said Ignition Coil E Promary/Secondary Circut mal****ion. I replaced both the spark plug and the ignition coil for tgat cylinder (Cylinder 5 Coil E) and the engine is still missing and throwing code. Every now and then I also get a Cylinder 8 misfire code. and another code saying that engine bank is running lean. Any Ideas?

 

Did you change the right plug and coil? #5 is the front cylinder, driver's side.

How many miles on the truck, plugs, and what brand plugs are in it?

 

Its got 173000. And yep it was for sure the right plug. I actually just went ahead and changed all my plugs. And I know Motorcraft.plugs are suggested but I put Autolite Platinums in . It originally had.motorcraft though. Also update i got cylinder 5 to stop missing but now cylinder 8 is missing. I have engine code saying banks 1 and 2 are running lean and the exhaust smells REALLY rich.

 

You have a major vacuum leak or air entering the intake after the MAF.

Good luck with those Autolites. Motorcrafts are suggested for a reason.