I recently removed my NX kit off my 14 GT. I installed 1* colder plugs. Now that the kit is removed is their any benefit to putting in factory plugs back in or can/should i just leave the colder plugs in?
I "believe" the stock hotter plugs resist fouling better, which probably wouldn't be a problem unless you were stuck in traffic. I doubt you would have any problems leaving them in until it is time to swap them. Under full throttle, you are less likely to get ping with the colder plug. No ping is good, with ping, the computer pulls timing. I'd leave them in there if all seems well, unless someone pops in and says something I didn't consider or know.
I run 1 step colder all the time bc I have the NX kit as well. The only thing I've ever noticed is on really cold days is a bit of stumbling on cold holes in the morning. Otherwise, it drives like stock so, I'd just leave them in. 1 step colder won't foul unless you live in the arctic.