It does not have to be plugged in all the time, but since it's a pain I just leave the by pass. The PCM swap is only for using the performance tunes. If you just want to do tire size, gears and a what not you don't have to do that.I have a few questions - I just got a Flashcal for my new re-gear and 37" tires. I see that I can upgrade my Flashcal to a Flashpaq for a discount through the software. Do I still need to do a PCM swap for this? The description does not state that I do.
Also, do I need to leave the bypass module plugged in all the time for my tunes / adjustments for gears / tires / etc. to stay active?