Originally Posted by TVT_DESIGN

We've sold several kits to owners that alreay have an ECU tune and the kit works fine. It will not work with the stock ECU tune. All aftermarket ECU tuned lean out the fuel trim and this is what is needed to allow bigger injectors to run without becoming overly rich. Our tune is more fine tuned for the larger injectors and is what the quoted HP is from. You will more then likely be within 2-3% of our advertised HP with a similar tune from Inmotion, Upsolute, etc.