Whiskey Tango Foxtrot ?!?!?!?!??!

He lost mpg, not power.

I don’t know if the 98’s have the DIC - how are you checking mpg? Filling tank the same amount each time and recording miles? How may tanks of gas have you gone through so far?

And I wouldn’t waste money on a Hypertech for any type of tuning. It’s handy for changing gear ratios, tire size, etc, but not for its tuning.