Description
631Z-31T D&D 2-into-1 Diablo Gato Black for 2009-2016 Harley FLH/FLT Touring Models
Check out our video on the Diablo Gato “Devil Cat” D&D Exhaust System. This is on our 2014 Street Glide.
The D&D 631Z-31 Black Diablo Gato 2:1 Exhaust is a stepped header system engineered for serious Touring performance. At the head, the headers step from 1 7/8″ to 2″ and finish at 2 1/2″ where the muffler meets the header. As a result, exhaust velocity improves while maintaining strong low-end torque.
Every Diablo Gato full system comes complete with heat shields, exhaust gaskets, quality flanges, a bolt kit, and a performance baffle, so there is no need to purchase additional installation hardware.
Moreover, each system is designed to increase low-end torque and overall horsepower. With proper tuning, riders can see performance gains of up to 12%, depending on engine setup.
The 4″ muffler housing features a 2 1/2″ perforated baffle core, making it ideal for motors up to 131 cubic inches. Because of this design, the exhaust delivers a deep, aggressive tone without sacrificing rideability.
In addition, the Diablo Gato includes both 12mm and 18mm O2 bungs, allowing compatibility with ThunderMax Auto Tune and Dynojet Auto Tune modules.
You can also customize your look by selecting your preferred exhaust tip from the dropdown menu. For riders running wrapped bags or wanting a true dual appearance, matching dummy pipes are available.
Key Features:
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Stepped headers: 1 7/8″ → 2″ → 2 1/2″
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4″ muffler housing
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2 1/2″ perforated baffle core (up to 131″ motors)
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Up to 12% performance increase with proper tuning
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Includes heat shields, flanges, gaskets, and bolt kit
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12mm & 18mm O2 sensor bungs
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Deep, aggressive Diablo Gato tone
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Optional matching dummy pipes available
