Banks Power
Part Number: 66682

2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)

$637.38 CAD
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs
  • 2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)-Tuning-Banks Power-66682-Dirty Diesel Customs

Banks Power
Part Number: 66682

2017-2019 Duramax L5P Derringer GEN2 Tuner (66682)

$637.38 CAD

Includes Free Expedited Shipping!

The GEN2 Derringer Tuner for the L5P Duramax is the updated version of their groundbreaking first generation Derringer Tuner. This L5P Tuner will safely make minor changes to your 2017-2019 GM and add 61hp & 112ft-lb without modifying your emissions system. This will push your L5P past 1000ft-lb of torque with no other modifications!

Fits: 2017-2019 L5P Duramax 2500/3500 6.6L 

If you're looking to tune your L5P Duramax the Derringer GEN2 Tuner is the answer. Gale Banks was one of the engineers behind the L5P Duramax, so it shouldn't come as a surprise Banks was the first company to 'break into' the L5P ECU. 

The GEN2 Derringer is a plug-and-play solution for the L5P Duramax. It connects to your truck via the OBDII port and gives you 3 different power levels to choose from and has ActiveSafety to protect your engine. The Derringer doesn't write anything on your ECU, it only adapts the parameters to safely make more power. This means the tuner is untraceable by the dealer and will not void your warranty.



  • Simple Install - Plug and Play
  • Loaded with Features
  • Adds 61hp & 112ft-lb
  • Warranty Friendly - Untraceable 
  • Works When Using Cruise Control
  • ActiveSafety Protects your Engine & Drivetrain
  • 3 Power Levels 
  • Toggle Switch for Tunes


The Derringer will result in power gains across the full operating RPM range, from idle to redline you'll notice significant gains in your L5P. The Derringer is dyno calibrated to use multiple data inputs such as throttle position, rpm, speed, AFR, knock, and coolant temperature to optimize adjustments to your ECU. 

It allows you to switch between 3 settings Stock, Plus, and Sport. Sport produces the largest power gains available for the L5P while the Plus setting is designed for work use and has a great mid-range feel for towing trailers or a loaded work truck. 

The Derringer tuner — When it comes down to it, you want a real L5P tuner. You want something that makes big power and doesn’t kill your truck. After all, you just spent a lot of money on that beast. The Banks Gen2 Derringer L5P tuner is the only option you should be plugging into your truck. Banks saw the numbers the competition was claiming and called bullshit, they tested every other tuner on the same dyno, same day, same weather conditions, with the same technician… Same damn test, period! There’s only so much you can do by just intercepting the fuel rail pressure sensor. That’s where all the others fall short. The Derringer is the only tuner that actually utilizes your truck’s ECU to make intelligent calculations!


Auto Rate

Unlike other tuners that use a fixed flash tune, the Derringer Tuner is constantly adjusting to the conditions to provide peak performance in every unique scenario. By utilizing the OBDII port, the Derringer fine-tunes the power levels on the fly without having to adjust the power levels.

  • Exhaust Gas Temperature (EGT) – The Derringer senses your engine’s EGT and intelligently modulates fueling to maintain a safe maximum EGT, protecting your turbo and engine.
  • Altitude compensation – The Derringer senses ambient air pressure, controlling the turbocharger to maintain added boost and power as altitude increases.
  • Diesel Particulate Filter (DPF) Regen – The Derringer tuner constantly monitors your DPF regen status and will optimize its calibration to ensure the DPF regen process completes successfully.
  • Accelerator Pedal Monitoring – The Derringer senses accelerator pedal position to roll in additional power progressively, optimizing part-throttle fuel economy and giving max power when you ask for it.
  • Coolant Temperature Monitoring – The Derringer senses coolant temp to control added power. During warmup, no power is added below 120° F, then power is ramped in and fully available above 150° If the coolant overheats for any reason, the Derringer starts removing its power at 230° F and additional power is totally removed if you exceed 240° F.
  • Full Power Timer – If set on Sport level, the Derringer allows for 30 seconds of wide open throttle before transitioning to the recommended power level for sustained tow/haul. (Our research has shown that the stock L5P when at full power will hit 1450° EGT and after a minute or so will pull out fuel to cool things down. So, we do the same thing.)

TransCommand® Active Transmission Safety System

In addition to AutoRate Adaptive Tuning, the Derringer utilizes the key engine and transmission parameters to enhance shift performance and improve the longevity of your transmission. Because the competitors lack the essential OBD-II data, they always add power at wide open throttle—no matter what! This can cause excessive transmission slip, torque converter clutch slip and even 170 HP engine derate in order for the transmission to complete the shift. This harms the overall performance and degrades your transmission. The Derringer is meticulously calibrated and extensively tested to properly modulate power during shifting, optimizing performance and safety.

  • Intelligent Shift Tuning – The transmission shift request signal is monitored to optimize the power level prior to the shift protecting the transmission, increasing shift speed and avoiding ECU power derates.
  • Boost and Fuel by Gear – Gear based calibration allows for optimum traction and performance
  • Torque Converter Clutch Slip Monitoring – The Derringer adjusts to modulate TCC slip to safe levels.
  • Transmission Slip Monitoring – The Derringer adjusts calibration to modulate transmission slip to safe levels


The Derringer is the only tuner on the market to include ‘Active Safety’, an active failsafe system that utilizes bypass relays to smoothly transition your vehicle to stock power levels in the event of any trouble signs in the Derringer. The system constantly monitors various parameters at over 50 times a second to ensure that everything is operating as it should. If any competitive tuners lose power or fail in any way, they will instantly trigger a “limp home” mode where all power is lost and the vehicle dangerously slows to a crawl. If the same fault condition occurs to the Derringer it will gracefully remove its additional power and return to stock power levels without a hitch.

  • Internal self-diagnostics checks the health of the system 50 times per second
  • Monitors MAP and FRP signals for out of range condition (disconnected or short circuit)
  • Watchdog timer constantly monitors CPU activity
  • Active safety engages if 12-volt power is lost to the Derringer tuner

Stock L5P Turbo Limitations

The factory turbocharger on the L5P is done at 505hp, that's a gain of 60 horsepower. Past that, the turbine drive pressures & EGT's increase to a point where no more boost is available safely. Anyone who claims they can produce more power from the OEM turbocharger doesn't understand the engine. 

Part Number: 66682

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