I wouldn't do the resistior mod. The resistor hooks up to the intake air temp sensor and tricks it into thinking colder air is coming in. This is good and will make power, but the sensor is one of the things that keeps the car from detonating when engine and outside air temps are too hot. If you bypass the sensor with the resistor, you can cause detonation to occur which can ruin your engine if it's bad enough. For this reason alone, computer chips are worth the investment, becuase they modify the computer in the correct way.