Re-Flash or save $ and SCT w/ custom
Dealer says I need an update, truck has the original 2004 programming and gets great milage in the 20's. I understand that a re-flash will kill my mpg.
I'm having surging and rough idle which is why it is at the dealer in the first place.
I'm planning to put a tune on it anyway so I'm wondering if I should just save the re-flash money and get my livewire right now.
What are the downfalls of not doing the factory re-flash prior to custom tuning? Will my symptoms persist even with the tunes without the re-flash?
It's not that much to flash it but I don't want it to be a waste of $ AND kill my milage if the tunes will fix it anyway.