Poor Acceleration Performance after codes P0304, p0303, P0300


I have a 2007 F150 with the 5.4 Triton V 8. I began having so rough acceleration from 40 -50 mph. I learned that this could be caused by faulty plugs and coils so I began to replace them. I replaced the plugs and coils on cylinders 1,2, 5,6,7,8 but waited to do do cylinders 3 and 4 because you have to remove the computer. I began to get p0304 codes every once in a while, but waited until I had enough time to do the job right.

Last weekend I took my son to Fort Worth and back, a trip of about 3hrs each way. On the way home I had three misfires P0304, P0303, and P0300. My truck began to accelerate poorly and it began having trouble accelerating quickly and behaved as if the transmission might be slipping.

Today I changed the cylinder 1 & 2 plugs and coils and no longer have any codes. But I still have the acceleration issue, but only when I try to accelerate quickly. The Rms will go up until the gear changes and there is a weird noise. There are no issues in accelerating or gear change when gradually accelerating only when you floor it.

Where do I go from here?


Comments (2)
No. 1-2

At this point all the coil on plugs and spark plugs have been changed.



best to change all the coil on plugs and all the spark plugs at the same time, start theree