more sputtering

[BigSur]

Try catching Cody on the chat support. I've had success that way.

Good luck with your issue. My truck just plain doesn't like the performance tune; I had the same issue you do. I've permanently switched back to the canned tow tune, and I'm completely happy with that. Still love the Gryphon. IMO the gains b/w the 87 canned tow and an 87 custom performance are VERY minimal. I actually think I noticed more power when I switched back, but that was becuase the performance tune had been compromised and tweaked over and over again in the attempt to eliminate the sputtering issue.

Either way, they will work with you until you're happy. Good luck.