Re: G-force chips
Its probably some resistors and such designed to fool the ecm into thinking ambient temps are different or something. Essentially making the engine run way different than it was designed too.
Jet performance makes chips too, though more expensive. A user on here had one and after some time was experiencing issues. Finally turned into a CEL and a Reduced Engine Power message. They pulled the chip and it was good to go again.
A proper tune is really the only option. And even so, the cost for a tune to gain nearly 15hp is pretty well worth it and reasonable IMO