If you have have our one of our MERCENARY Autocals currently and have changed/added modifications to your vehicle you may request a re-tune. Please add this item to your cart and list all of your modifications in the "note to seller" area before checking out. Please note that minor modifications (adding a lift pump, changing intake/exhaust, adding gauges, etc.) do not warrant a re-tune. Changing to larger injectors, turbo(s), injection pump(s), or a built transmission may require a re-tune for your vehicle to run properly. AUTOCAL LITE TUNERS cannot be re-tuned. They must be upgraded to a level 1 or higher for custom tuning. Please allow 24-48 business hours for your re-tune to be processed.