How to Tune Your Mustang using an SCT X3 Power Flash Programmer

You should now see a menu option that instructs you to begin the program or cancel the program. If you are unsure about a setting, you can hit "Cancel" at this point and run through the set up process again. If you feel confident regarding your set up, select "Begin Program". The "Download Tune" menu will appear. Turn the key to the on position, but do not start the engine. The programmer will now begin to tune your system. DO NOT unplug the tuner during this phase. Also DO NOT turn the ignition to off. Let the tuner run its course. When it is finished, the "Download Complete" screen will appear. Turn the key to the off position, and then press "Select".