Hello, hoping someone here can help me. 2020 F150 with 2.7L ecoboost. 97k miles Started to get some engine shuddering when accelerating about 2 months ago. Was overdue for spark plugs, so replaced all 6. Did not have motorcraft, so replaced with NGK iridium. Those come pre-gapped @ .032. Carefully checked with finger Guage as I was switching, all were good. Problem went away for about a month. Started shuddering again when accelerating, but throwing no codes. Tried to pass a car on interstate just before Christmas, truck starts shuddering BAD. Engine light flashes for a few seconds, then stays on. Codes reads P0305. Cylinder 5 misfire detected. Replace coil pack on cylinder 5. Old pack has no visible abnormalities. Clear codes. Truck still shuddering on moderate acceleration. No codes. Couple days later, engine starts shuddering BAD again while accelerating on interstate. Engine light flashed again, but did not stay lit. Check codes, 4 pending codes. P0300 Multiple cylinder misfire, P0305, P0306, and one more cylinder that I don't remember. Slip of paper I jotted codes down on got lost. Check codes again today because I lost the previous slip of paper, and under pending codes only had P0305, cylinder 5 again. Just a recap, the issue started before I changed the spark plugs, is not throwing a permanent code that causes the engine light to illuminate, and has had pending codes for multiple cylinders.

Any help would be much appreciated.

 

I would pull the plugs and verify that they did not crack during installation. May also want to check to see if they are torqued down and not loose. Verify that the coil pack plug connectors are on tight and click in place. Good luck.

Tom