I'm just wanting to know how tuners really work and if they need to be plugged in all the time? looking for something for my 06' 5.4L v8 triton F-150

 

Get a SCT X4 from MPT or 5Star with CUSTOM tunes. No, they don't need to be left plugged in, only needed when loading tunes.

Bully Dog gas engine programmers are not very good. Their diesel products are much better.

 

You do realize that Bully Dog and SCT have now merged? I would think the tunes etc should become similar?