Originally Posted by FullBoostRacing
So how come the Driven Fab flex fuel is the only kit without a harness that addresses the fuel vap canister? Every time I plug the harness that came with the driven kit into my fuel pressure sensor the car starts idling a little funny and I get random fuel smells. If I put the OEM harness back on the OEM fuel pressure sensor and everything is good again. So I am assuming this is related to the fact other kits have this extra harness that addresses the evap canister. So...... Does anyone know how to manually splice the fuel evap canister into this FelxFuel kit?
The reason why you smell fuel is because when you use the flex fuel kit it "eliminates" the evap system as part of the car. The evap canister is looking for a 0-5v signal from the pressure sensor to determine when it needs to open or close. The flex sensor robs this pressure sensor signal back to the ECU to determine the E content, via Tephra V3 and a tune. If you aren't on flex fuel yet (tuned), then the ECU thinks
the sensor is sending it a reading that its not, and opens/ the evap canister. This would be why you get a lot of "fuel smell". So until you actually get tuned on flex and Tephra V3, I would leave the stock connectors plugged in.
FWIW, the other kits that have a "splice" to the Evap solenoid are merely robbing it of 12v power, to power their sensors and other electronic components. All the control of the canister is still determined by the ECU via tuning.
I asked this same exact question here
because I didn't need a PnP kit, as I have my own fuel system and would rather have a dedicated gauge.