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Our Flex Fuel kits are in stock and ready to ship!

2014-2019 Chevrolet Silverado 1500 Lethal Garage Flex Fuel Kit

Regular price $299.99 Sale price $359.99

Unit price per 

Our custom E85 Flex Fuel kit for the 15-19 Chevrolet Silverado with a 5.3L 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). PLEASE! Verify the harness plug location on your vehicle before purchasing, see the install video below for location. Returns will incur a restock fee.

Note: This kit can also work for the Tahoe and Suburban if you have the frame rail connection point as seen in the install video below. 

This kit is assembled by Lethal Garage 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 - Gen5DIY custom plug & play power harness & ECU tap. (Made in the USA)
  • Two Year Warranty on all GM parts as provided by GM & lifetime warranty on the Gen5DIY harness that covers any defects in craftsmanship.
  • 4 - Zip ties for install

Our product is designed to tuck away and be hidden under the vehicle away from the engine allowing 100% concealment if your hood is popped. Our kit installs under the back side of the cab in front of the fuel tank where the factory sensor would have installed if your vehicle came with it. 

Vehicle Fitment:

  • 2014 Chevrolet Silverado 1500 models with the 5.3L or 6.2L engine
  • 2015-2018 Chevrolet Silverado's with the 5.3L or 6.2L engine
  • 2019 Chevrolet Silverado LD model with the 5.3L or 6.2L engine
  • 2019 Chevrolet Silverado HD models with the 5.3L or 6.2L engine
  • This will not fit the New Body Style 2019+ models (Classic Body style only)


  • This kits harness uses OEM connectors in tandem with OEM products. Fit and finish look 100% stock under your vehicle. Your truck will pick up 10-15rwhp on e78 or better depending on the tune.
  • Note: While the GM flex fuel sensor can be installed and works perfectly fine to run pump gas with your vehicle without a tune, to run E85 your truck must have a tune to run E85 fuel. 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.

Install Guide: 

Note: Verify your truck or SUV has the Flex Fuel harness plug located on the frame rail of the vehicle just behind the cab of the truck. See the install video for precise location. 



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

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