Hypertech 32002 Max Energy Power Programmer for 997-04 GM 5.7L LSi 2000-05 GM 3.8L Power tuning for regular, premium and E-85/Flex fuel vehicles Adjustable top speed limiter and engine rev limiter (not available on all vehicles) Speedometer/odometer recalibration for non-stock tires and rear end gears (not available on all vehicles) Automatic transmission shift point and shift firmness adjustments (most applications) Features easy plug and play design