Handheld engine programmers and tuners are a great way to squeeze hidden power out of your Jeep's engine, but that's not all they can do! If you've installed larger wheels and tires on your Jeep, or even re-geared your axles, they can calibrate for the differences to ensure your speedometer and odometer are reading correctly. If you've added bolt on performance items like an air intake or exhaust, some offer additional programming features to accommodate those specific modifications.
A lot of handheld programmers are even designed to be left connected to your Jeep while you drive to provide you with additional vehicle feedback. Some give you more detailed diagnostic information, such as transmission and intake air temperatures. Others even allow you to add additional accessories that you can control with digital switches right on the unit's touchscreen.