Back in the day, a computer took up a whole room, and engines had carburetors. In the late 1980s and 90s, EFI (electronic fuel injection) became widespread. As engines equipped with EFI became mainstream, the benefits of having a computer control the idle and fuel/air mixture, among other things, were accepted. Fast forward to the 2010s. Computers more or less control the entire powertrain on all new vehicles and many other systems, such as brakes and HVAC. As computers gradually took over the motor vehicle, car enthusiasts found that this added a new level of complexity to engine swaps, among other things. One can’t simply throw a carbureted 350 small block into a brand-new straight-drive CJ-7 anymore. With a new vehicle, it’s just not that simple. When you drop in a V8 engine, the computer won’t simply adapt to the new hardware. Sometimes the shift points for the automatic transmission are off. And sometimes the engine won’t run correctly, even with the new V8 computer. While you can dial in and reprogram these electronics to give your Jeep an OEM feel, these settings can also be adjusted to your individual specifications. With a custom program, you can control things like your transmission shift points, causing the Jeep to shift higher in the RPM range. This results in more power and prevents “lugging," for example. Arrington offers genuine MOPAR PCMs that are custom programmed to ensure your new engine works with your application. Other aftermarket products, like Piggyback Tuning Systems, offer tuning options that plug directly into your existing PCM. You can modify these with a laptop or smaller handheld tuner and tune them on the fly. You can adjust the fuel/air mixture in your engine, optimize spark timing and more, including the transmission shift points. In this day and age where computers are controlling more and more in our daily lives, there's no reason to tolerate sub-par Jeep performance. Make sure the on-board computer has the proper tune. The difference will be night and day, we promise!