Fixed syntax
This will not make your car run leaner with the added fuel line, you're adding 3ft, not a mile. Just be sure to prime the lines before starting the car. The car will correct itself with a reset ECU, and run even better with corrected maps.
For those with stock cars with this issue, it is not a warranty item, but a design flaw, you have the option of doing the mod, but is best to bring it to the dealership.