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Lethal Garage Flex Fuel Kits are In-Stock and Shipping! Snag your Spring Savings NOW!

2008-2014 Chevrolet Silverado/Sierra Lethal Garage Flex Fuel Kit - Coming Soon

Regular price $289.99 Sale price $329.99

Unit price per 

only 0 left in stock

Our custom E85 Flex Fuel kit for the 2008-2014 Chevrolet Silverado & GMC Sierra with a 4.8L, 5.3L, 6.0L (HD Models), or 6.2L engine is just what you need for more power, savings on fuel costs, and a better smelling ride... (Okay, that last one is subjective).

Lethal Garage assembles this kit, and it includes the following:

  • 1 - GM OEM Flex Fuel Sensor
  • 1 - Stainless Steel Braided PTFE OEM Style Fuel Line (Made in the USA)
  • 1 - Fuel Line Disconnect Tool (Made in the USA)
  • 1 - Custom plug & play power harness & ECU tap. (Made in the USA)
  • Two Two-year warranty on all GM parts & lifetime warranty on the Gen5DIY harness that covers any defects in craftsmanship.
  • Includes zip ties for a clean install..  

Our product is designed to tuck away and be hidden, allowing 100% concealment if your hood is popped. 

Vehicle Fitment:

  • 2008-2014 Chevrolet Silverado 1500 models with the 4,8L, 5.3L or 6.2L engine
  • 2008-2014 Chevrolet Silverado HD Models with the 6.0L engine


  • This kit harness uses OEM connectors in tandem with OEM products. Fit and finish look 100% stock under your vehicle's hood. Depending on the tune, your truck will pick up 10-15rwhp on e78 or better.
  • While this kit can be installed and will work perfectly fine to run pump gas without a tune, to run E85 your truck must have a tune. DO NOT INSTALL & RUN E85 WITHOUT A PROPER TUNE. Make sure your tuner has verified your sensor is hooked up and reading the ethanol content before adding E85 to your vehicle.
  • Until your vehicle is tuned and the flex sensor is turned on in the ECU, you may have a CEL (Check Engine Light), as the ECU won't know what you plugged into it until it is tuned.

Install Guide: 

~Coming Soon~


WARNING California Residents - cancer (and/or reproductive harm) -

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