If you have a 2012 to 2013 model year Cadillac CTS sedan, or 2014 CTS coupe, with the 3.6 Direct Injection V6, verified by the 8th digit of your VIN being a "3", you're on the right page for your vehicle!




Overkill is proud to be a specialist of the GM Direct Injection V6 family and with a special focus on the 3.6 LFX V6. With Overkill tuning, you'll notice right away much improved throttle responsiveness and acceleration and improved transmission performance which will feel lighter and easier to drive. We also support many of our exclusive performance products including E85 flex fuel tuning.

What you'll notice:
  • Horsepower gains of 20+ on 91 octane and 10-15 on 87 octane
  • Improved response from the throttle pedal, NO NEED FOR EXTERNAL THROTTLE BOOSTERS!
  • Increased fuel mileage possible
  • Fully rewritten transmission shift points will downshift with less throttle input, upshift at better times, reduce bogging around town, and make the vehicle feel lighter and easier to drive
  • Tuning For Aftermarket Intakes
  • Tuning for Our Flex Fuel Conversion Kit to use E85 or Gasoline as you desire!
  • Speed limiter removed, Rev Limiter in Park raised
  • No Charge Retuning For Future Modifications for as long as you own your CTS


What you'll get with your purchase:
  • An Autocal handheld tuning device, with software on a USB drive
  • Overkill 91/93 octane tune
  • Overkill 87 octane tune
  • Overkill E85 Flex Fuel tuning in each tune (if you get our Flex Fuel conversion kit)
  • Tuning support for datalogging and custom revisions
  • Tuning support for new mods as you add them, for as long as you own the vehicle


Why get an Overkill tune versus the competition?
  • Specialized in the GM Direct Injection V6 motors. From revised cam phasing, fully reconstructing spark timing tables and fully revised throttle calibration, an Overkill tune is more comprehensive than what you'll get at your local dyno shop, or a do-all tuning provider.
  • Datalogging. You'll get your Overkill tunes but it doesn't stop there. You can scan with our handheld while driving and send that data for review and tune updates, to get a tune that's more customized for your vehicle
  • Support for your mods. Not only are we the only company with an E85 Flex Fuel conversion kit or a larger 80mm throttle body kit, but we also have the right tuning to ensure you get the most from them!
  • Retunes. With our handheld, retuning for your future modifications is complimentary and easy to provide



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Autocal Handheld: The best way for us to provide 2012+ CTS 3.6 tuning for you is through our Autocal handheld system. The Autocal handheld allows you to take the handheld to the vehicle, read the factory file, upload our Overkill tunes and provide scan data, with no laptop required. Return to stock calibration whenever you want, apply updates and retunes easily through email with us and Overkill retuning is available at no charge for as long as you own your CTS.




Want a great deal? Of course you do! This combo pairs Overkill Tuning through our Autocal handheld with our E85 Flex Fuel kit. You'll get Overkill tuning for 87 and 91/93 octane gasoline, plus tuning for E85 Ethanol fuel which out performs its gasoline counterparts.

The flex fuel kit retrofits a GM flex fuel sensor into the fuel system, and relays a precise ethanol content of the fuel in the system to the computer. In combination with Overkill tuning, the computer will adjust air/fuel targets for any ethanol blend. You can switch between gasoline and E85 ethanol as desired without requiring any changes to the vehicle once this kit and Overkill tuning is installed. This is by far the best bang for your performance buck on a 3.6 LFX V6!

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The only larger throttle body for the 2012+ LFX 3.6 is available here at Overkill. The factory throttle body is 72mm, as are ported units on the market. Our 80mm throttle body solution dwarfs the stock unit and will allow the your engine to breathe, improving horsepower, improving throttle response (particularly with Overkill tuning) and changes the intake note of the V6 to a deeper growl at heavy throttle.

This kit bolts to the stock intake manifold with no tuning required, but works best when used with a ported intake manifold modified to a matching 80mm inlet. Kit uses a brand new throttle body with an aluminum adapter plate and stainless steel bolts. Newest kits now come with an o-ring seal! There is no core charges, we don't need you to send in your factory throttle body.

Tip: This throttle body has a 3.5" clamping area, compared to the factory throttle body of 3". Ensure you have a solution available before installing the throttle body! Look below for what we offer for your current intake.

Need an intake coupler?






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