2006 5.4L Intermittent Dead Miss

[bskouby]

Originally Posted by lbjailer

If you had a miss-fire wouldn't it be there even without using a tuner? But if that fixes your issue, let us know.

The truck would only misfire when running on the custom tunes. Stock, tranny only, and the canned tunes did not exhibit these symptoms. I wonder if the tune stressed the ignition system enough to not be able to keep up due to the battery and/or possibly loose plug. Only time will tell.