Okay, I am new forums but I have a 2018 f150 with the 5.0. The other night the truck was running fine, all day and the whole ride home until I pulled in my neighborhood. The truck stalled and I restarted it, but it ran very rough otw home and the check engine light came on and started flashing. I had the code read the next day and it said misfire in cylinder 6. I ordered new coil packs (motor-craft) and replaced all of them and the plugs. Now it is running even more rough and has multiple misfires. I have no idea what is going on or how to fix it. Any help would be appreciated.

 

I would check to make sure you plugged in and seated the Coll pack connectors properly first. Next would be to read the codes and check those cylinders spark plugs to make sure that they did not crack during installation. There are a lot of counterfeit spark plugs out there, especially on Amazon from what I hear. And they crack easily. Where did you buy your plugs and coil packs?

Good luck
Tom

 

I ordered the coil packs from parts geek but I bought the plugs from Napa. The plugs are ngk laser platinum

 

My 2018 5.0 F150 has a misfire under load.

Cylinder 6 and 8 are both missfiring. I've replaced the spark plugs and moved the coil packs from working cylinders to bad cylinders. Recently I replaced the two direct injectors for cylinder 6 & 8. Missfire continued. I'm not sure what to do from here. Compression issue?