Is it worth changing the factory tune on this PCM? I have a '98 Z71, almost entirely stock with the exception of dual exhaust (factory 2 into 1 muffler removed for 2 mufflers), a descreen MAF, and removed airbox. I manage 16.5-17.5 mpg on pure highway runs and summer grade gas, but mix driving, at least in the winter is horrible at 13-14mpg.
I know the 411 swap is common, and fairly simple - but is it worth it in my case (truck will not be modded beyond what it has been other than maybe the throttle blase). Or will sticking with the black box pcm get me by - and is it worth spending the license on?
Thank you