AEV's ProCal Module
The Jeep Wrangler JK is a very capable vehicle in factory form, but once a suspension lift is added with larger tires and wheels, the Jeep's complex computer and electronics are befuddled. These electronic glitches lead to handling problems and poor on- and off-road drivetrain performance.
American Expedition Vehicles has ingeniously engineered the ProCal Module, which quickly and easily recalibrates the JK's ECM. The best benefit of the ProCal is its ability to correct the speedometer and gear ratio when larger tires are installed. If the speedometer is left uncorrected, there is a major degradation in stability control (ESP), engine performance, and transmission shifting. The ProCal module is inexpensive and an easy way to bring your JK's performance levels back up to snuff.