I'm new to this site..I really need help y'all...I just changed out my spark plugs. I removed the fuel rail and had to reseat the injectors. That wasnt too bad,but now my f150 Lariat is knocking terribly...Any help out there??

 

Look at the old ones and make sure nothin broke off. If not, you may have had something fall down into the cylinder. I would not run it again until you know for sure. May have to rent a scope to look into the spark plug holes.

 

Could you possible be able to mix up wires going to the COPS causing 2 of them to fire at the wrong time ???

Does it run OK other than the knock??

 

I'm scared to run it any longer...I dont think anything went into the plug ports..the knocking is pretty bad

 

are the spark plug direct replacements? or did you change brands or length of the spark plugs? hard knocking i would double check the spark plug wires, maybe they got mixed