Misfire

[Jeff Simon]

I've had a misfire code keep coming up on my 05 explorer xlt 4.0 by for the last 6 months. I've replaced plugs, plug wires, coil pack, injectors, fuel filter, EGR, fuel pressure sensor & air filter. I get different cylinder misfire codes everytime I reset and check it. When I'm accelerate the check engine light will start flashing and the motor will turn off. I shut it off and restart it. Than it will do the same thing after a few miles down the road. Please help.

 

[XLTyler83]

Was it by chance a Cheap after market coil pack? I’ve seen those become a nightmare. Also motorcraft plugs are the best.

 

[Drewmcg]

Bad timing on one bank can cause random misfires. Mileage? Any rattle at startup?

Sometimes, but less likely, clogged cat on one bank can cause intermittent misfires (drive to excessive backpressure). A mechanic can check for this (Eric O. did a video on SMA's YouTube channel, though not on an Explorer).

If you replaced an OEM coil pack with an aftermarket one, get the OEM part back (if you can), and consider re-installing it. See my recent tale of woe on this forum for reason.

 

[Drewmcg]

Also, what are your fuel trims? Maybe excessive vacuum leak?

 

[Jeff Simon]

Was it by chance a Cheap after market coil pack? I’ve seen those become a nightmare. Also motorcraft plugs are the best.

Motor craft plugs and coil pack.