I have a 2010 Jeep Wrangler Rubicon with a 5.7 Hemi installed by AEV (2007-2011 JK using a 2011+ VVT 5.7L Engine) and the 5-45RFE Transmission. I was able to change the gear ratio and tire size with the VCM Editor with no issues. I was able to read the Tune with the VCM Editor with no error messages or issues. I have messaged AEV about tuning the PCM and they are telling me, "Some shops have been successful, most have not. If the PCM needs to be recalibrated because of a tune gone wrong we charge a $250 fee plus shipping to reinstall our calibration." So, this clearly makes me concerned with making any changes to the program; however, if some shops have been successful, why? I would clearly like to make tuning tweaks, but I would be happy with just being able to adjust the Driver Demand settings and the cooling fan settings. Has anyone successfully made any tune changes to an AEV Hemi conversion with out rendering the vehicle inoperable?