I have an '04 Tahoe. I installed 20" wheels and purchased a Hypertech Programer to adjust the speedo. Since my wife drives the tahoe I programed it for 87 octane and left the rest of the settings stock. When I did this the driver information center read "Reduced Engine Power". I could understand why. A few weeks later when I was experimenting I reprogramed it for 93 octane and the driver info center read "Reduced Engine Power. I was somewhat confused. Just being curious, I returned the stock programing and the driver info center read"Rerduced Engine Power".
WHAT GIVES?

TOMMY