IMPORTANT: If you follow these instructions, you will be making modifications to your fuel system. As such, there are major safety risks involved. If the hardware is not installed correctly, a fuel leak will occur. A fuel leak can cause a fire hazard. If you are, in any way, unsure about the installation process, we HIGHLY recommend having this kit installed by a professional. It won't take them more than a few minutes to install the fuel lines, and perhaps 1-2 hours to route and connect all wiring. OpenFlash Performance takes no responsibility for damages caused, directly or indirectly, installing this hardware upgrade/modification .


Before starting this installation process you will want to make sure there is very little (if any) fuel pressure in the fuel lines. You also want to make sure that the engine is cool to the touch to minimize any fire hazard. You should only attempt installation after the car/engine has been sitting (engine/ignition OFF) for some hours. Even so, you will experience some fuel leakage during the installation process. Be sure to have rags ready to sop and catch dripping fuel.


  1. Step 1: Identify the fuel line that you will be intercepting with the flex-fuel kit. In the picture below, it is circled. It is the one closest to you when standing in from of the vehicle.


  2.  Disconnect the fuel line using the correct fuel line disconnect tool(s). If you do not have a fuel line disconnect tools, they can be purchased from most auto parts stores. Again, you may need to catch some fuel spray when you pull off the fuel line. So have some rags handy.

    Here is a tool kit you can get for $5: http://www.harborfreight.com/6-piece-fuel-line-and-a-c-quick-disconnect-tool-97576.html

    And here is a generic (not specific to GT86) video showing how to use the tool: https://youtu.be/vRTjYAxvaCs


  3.  Connect the Flex Fuel kit fuel line as shown in the picture below. Make sure the connection is pushed all the way in and clicks securely.
  4. Connect the other Flex-Fuel kit fuel line to the fuel line that you disconnected in Step 2


  5. With both connections secure, you can secure the flex fuel sensor to the hard fuel lines going to the ABS module with the supplied zip ties. 
  6. Connect the Flex Fuel sensor's wiring harness.


  7. Locate the unused grommet on the firewall under the brake fluid reservoir. Removing this grommet will reveal the hole to route the Flex Fuel sensor's wiring harness.

  8. Using a razor blade cut an X-shaped incision in the center of the grommet. The route the wiring harness through the grommet and insert it back into the hole in the firewall. From the driver's side footwell, locate the wiring harness and pull it through to eliminate slack in the engine compartment.


  9. There are 3 wires in the wiring harness. 
    • Red is switched +12V Power. 
    • White is Ground. 
    • Orange is the Ethanol Content signal.

      Locate a switched +12v source in the fuse box near your left ankle when sitting in the driver's seat. It looks some what like what you see in the picture below. Ignore the two fuse jumpers at the bottom. They were used for some other aftermarket upgrades on our test vehicle. Locate the 15 amp fuse at the top right of the picture.


    • Carefully remove it using needle nose pliers (or the fuse pulling tool).


    • Insert two 15amp fuses into the fuse jumper included in the kit.


    • You will NOT be able to reuse the original fuse that you extracted. If you do not have two 15 amp fuses, you can get them at any hardware or auto parts store.
    • Crimp the fuse jumper to the red wire in the wiring harness. Then insert the fuse jumper into the empty fuse socket.


10. Crimp ground terminal to the white wire in the wiring harness and connect it to a the bolt that secures the fuse box. Take care to route the wiring carefully under the steering wheel areas so that it doesn't interfere with your feet or knees. Use the supplied zip ties to keep the wires from dangling too low.


11. Remove the 2 panels on each side of the transmission tunnel. To remove, just pull them forward and they will pop off.


With both panels removed you should be able to route the orange wire from the wiring harness through the gap. If necessary, you can use a straightened coat hanger to pull the wire through. Locate the EngineControl Unit (ECU). It is located just behind the glovebox (to the right). If you get your head in the passenger footwell and look upwards, you should be able to see the 4 white connectors that plug into it.


  • Unplug each connector and pull the ECU wiring harness downwards for easier access.


Locate the EVAP pressure sensor signal wire in ECU Connector A35. This wire will be orange with a black stripe.



Cut this wire. Be sure to leave at least a couple inches of wire so it iseasy to work with. Strip the end of the wire.



Using male and female crimp on terminals, connect the EVAP pressure sensor wire (the side that goes to the ECU connector) to the orange wire in the Flex Fuel wiring harness. The other side of the cut wire can be tucked away among the other wires going to the connector.You can put a small bit of electrical tape on the tip of the cut wire to ensure that it doesn't short against anything. If you ever wanted to go back to stock or remove the Flex Fuel kit, you can reconnect this wire by crimping on a mating connector and plug it back into the other side of the wire that connected to the Flex Fuel harness.


12. Plug the ECU connectors back into the ECU. Route the orange wire so that it cannot be accidentally kicked off by passenger's foot.

13. Update your OFT to the Flex Fuel Template provided along with this email. Upload appropriate Flex Fuel tune file to the OFT and flash it to your ECU. At this point, the custom E-Tuning process can begin!