2004 GTO Handheld SLP Custom DiabloSport II Tuner-Looking for the most powerful PCM-tuning tool on the market? Unlike typical off-the-shelf programmers, the DiabloSport II by SLP comes armed with an ultra-hot custom tune developed specifically for your vehicle application. Through extensive testing on our in-house dynamometer, our engineers were able to determine the precise levels of spark and fuel required to achieve optimal horsepower and torque at each rpm increment. In addition to its dyno-proven performance programming, this portable, easy-to-use unit allows you to fine-tune a wide range of computer-controlled powertrain functions for maximum power and drivability. Manipulate rev limiters; correct your speedometer for non-stock gear ratios and tire sizes; boost transmission line pressure for firmer, quicker shifts (automatic transmission only); remove the factory top-speed governor; and more?all in minutes and at the touch of a button. Shipping is not included.