2010 Silverado 5.3 87 octane tune...not satified.

[Austin66]

Hey,
I ran the MPG booster for about 2 weeks and then installed a new Borla cat back system.. I felt the truck very sluggish and shifts sounded sluggish..(now that I can hear them). So I changed to the 87 octane tune and I'm still not satisfied, I read about a lot of people doing cat backs with this tune and needing to make adjustment's to make it right. Now I'm looking to try the Diablo tune with 91 octane once I finish this tank... any suggestions????
Thanks,

[Spiceygoat]

What transmission and gearing do you have? Are you only doing an ECM tune or are you also doing a TCM tune? Have you changed any of the default settings for the 87 octane tune? Is AFM (DOD) still on?

[mikel]

No tune changes for a catback...you should notice a gain from the 87 tune, the MPG tune dies not add power...