I've been having troubles with misfires. I've gone through replaced all plugs and coil packs. I've cleaned my throttle body changed out both of my cats. They were no good after the original misfiring issues. I'm still getting random misfires with misfires on cylinder's 1 & 8. I've ran out of ideas of what's else can be done before I have to bite the bullet and take her to a mechanic. Any thoughts would be greatly appreciated.

 

Were the misfire codes on cyl 1 and 8 before as well? Is everything connected and plugged in tight? I would swap coils from 1 and 8 to two cylinders that are not misfiring and see if the codes follow. If not, I would then swap spark plugs and see if the code follows. If the codes stay in cyl 1 and 8 at that point, then look at the injectors, did you disconnect their plug?

 

And what brand of plugs and COP’s did you install... did you replace boots and springs also ?

 

Good point, these engines do like motorcraft plugs and the boots and springs usually cause more issues than the COP itself.

 

and the use of dielectric grease on the boot ends will seal out moisture...

 

I used accelerate cops new boots and springs. Used dielectric grease on all connections new motocraft plugs all the way around

 

you use the dielectric grease on the connections ??