'01 F150 #3 cylinder misfire
Friend is getting code for #3 cylinder misfire. 4 months ago it blew the same plug out, fixed it and installed new plug and coil pack and boot. Ran great. Last night he swapped coil pack with another cylinder just to see if
it was the coil pack. At idle it ran smooth but under load motor felt like it was shaking. Any ideas? Thanks.