I have a 2003 S10 ZR2 4.3L. I have K&N Cold air intake. Throttle Spacer. And FLowmasters. So I order a Hypertech Power programmer 3. Looking for a LIL more. They claim it will add HP, Stiffen up my shifting and give me better gas ml. So I install it with no problem. I set the fuel curve fro 87 gas because im a cheap fuck. I start her up and head out on the road. She warms up I give her gas and she PINGS like a mofo. I call them up and they tell me that because of my other mods I need to run 93 octane and still keep the fuel curve set @ 87 oct. To tell you the truth I feel nothing at all. But the shifting does seem alot stiffer. So now I have to pay for high octane for nothing. Any Help guys? I dont know much about engines.